Protein S-palmitoylation and cancer

BBACAN-88051; No. of pages: 14; 4C: 3 Biochimica et Biophysica Acta xxx (2015) xxx–xxx

Contents lists available at ScienceDirect

Biochimica et Biophysica Acta

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Protein S-palmitoylation and cancer

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Marc Yeste-Velasco a, Maurine E. Linder b, Yong-Jie Lu a,⁎

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Article history: Received 3 April 2015 Received in revised form 16 June 2015 Accepted 21 June 2015 Available online xxxx

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Keywords: DHHC Palmitoylation Cancer LYPLA

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Protein S-palmitoylation is a reversible posttranslational modification of proteins with fatty acids, an enzymatic process driven by a recently discovered family of protein acyltransferases (PATs) that are defined by a conserved catalytic domain characterized by a DHHC sequence motif. Protein S-palmitoylation has a prominent role in regulating protein location, trafficking and function. Recent studies of DHHC PATs and their functional effects have demonstrated that their dysregulation is associated with human diseases, including schizophrenia, X-linked mental retardation, and Huntington's Disease. A growing number of reports indicate an important role for DHHC proteins and their substrates in tumorigenesis. Whereas DHHC PATs comprise a family of 23 enzymes in humans, a smaller number of enzymes that remove palmitate have been identified and characterized as potential therapeutic targets. Here we review current knowledge of the enzymes that mediate reversible palmitoylation and their cancer-associated substrates and discuss potential therapeutic applications. © 2015 Published by Elsevier B.V.

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Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Overview of the functional consequences of protein S-palmitoylation . . . . . . . . . Enzymology of protein S-palmitoylation . . . . . . . . . . . . . . . . . . . . . . 3.1. DHHC palmitoyltransferases. . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Depalmitoylating enzymes . . . . . . . . . . . . . . . . . . . . . . . . . Roles of DHHC family members in cancer . . . . . . . . . . . . . . . . . . . . . . 4.1. DHHC2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2. DHHC3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3. DHHC5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4. DHHC7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5. DHHC8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6. DHHC9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7. DHHC11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8. DHHC14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9. DHHC17 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10. DHHC20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11. DHHC21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cancer-associated proteins regulated by palmitoylation . . . . . . . . . . . . . . . 5.1. Sustained proliferative signaling . . . . . . . . . . . . . . . . . . . . . . . 5.2. Resisting cell death. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3. Invasion and metastasis. . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4. Angiogenesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5. Induction of Inflammation, an enabling hallmark . . . . . . . . . . . . . . . Palmitoylation and sex steroid receptors . . . . . . . . . . . . . . . . . . . . . . The potential of targeting protein palmitoylation and DHHC proteins for cancer therapy . 7.1. Palmitoylation inhibitors . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2. Inhibition of depalmitoylation . . . . . . . . . . . . . . . . . . . . . . . .

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Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK Department of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA

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⁎ Corresponding author at: Centre for Molecular Oncology, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ, UK. E-mail address: [email protected] (Y.-J. Lu).

http://dx.doi.org/10.1016/j.bbcan.2015.06.004 0304-419X/© 2015 Published by Elsevier B.V.

Please cite this article as: M. Yeste-Velasco, et al., Protein S-palmitoylation and cancer, Biochim. Biophys. Acta (2015), http://dx.doi.org/10.1016/ j.bbcan.2015.06.004

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8. Concluding remarks . Conflict of interest . . . . Acknowledgments . . . . References. . . . . . . .

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Protein S-palmitoylation is a posttranslational modification in which palmitate or other long-chain fatty acids are added to proteins at cysteine residues through a reversible thioester linkage. The biological role and importance of protein palmitoylation has been understudied and underestimated for many years since its discovery 40 years ago. Recent technological advances in proteomics and cell imagining have increased understanding of the scope of the modification and its importance in regulating essential cellular functions. More than 400 human proteins have been detected as palmitoylated [1–4]. Both integral and peripheral membrane proteins are substrates. Signal transduction pathways are enriched in proteins modified with palmitate, with important functional consequences. Constitutive and regulated turnover of palmitate regulates membrane association and intracellular trafficking of signaling GTPases [5,6]. Numerous receptors, ion channels, and transporters are S-palmitoylated with diverse functional consequences, including the regulation of assembly, trafficking, and stability [7,8]. Protein S-palmitoylation is just one of several fatty acid modifications of proteins found in cells (Fig. 1) [9]. N-myristoylation of proteins is a well-characterized lipid modification that is often found in conjunction with protein S-palmitoylation on proteins such as Src-family kinases and heterotrimeric G proteins. Typically a co-translational modification, myristic acid is added to proteins through an amide linkage to the Nterminal glycine residue that is exposed following cleavage of the initiator methionine. The protein is subsequently S-palmitoylated at cysteine residues near the N-terminus. Similarly in Ras proteins and other small GTPases, which are modified with farnesyl or geranylgeranyl isoprenoids, S-palmitoylation occurs at cysteine residues near the isoprenylated Cterminus [10]. An emerging area of investigation is lysine-linked fatty acylation in which fatty acids are linked to the ε-amino group of lysine residues

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(Fig. 2). Although only a few substrates have been reported, interest in this modification is heightened by recent evidence that some members of the sirtuin family function to remove lysine-linked fatty acid from proteins [11,12]. Finally, fatty acid modifications also occur in the lumen of the secretory pathway and are catalyzed by members of a family of membranebound O-acyltransferases (MBOAT proteins) (Fig. 3). Substrates for MBOAT proteins include the secreted morphogens, Wnt and Hedgehog, and the neuropeptide hormone ghrelin. Ghrelin is unusual in having the short-chain fatty acid octanoate attached to serine, a modification that is required for its secretion. Wnt is modified with oxyester-linked palmitoleic acid, whereas Hedgehog is modified with amide-linked palmitate at the N-terminus of the protein. Inhibiting protein fatty acylation to target cancers driven by aberrant signaling through Wnt and Hh pathways is an active area of research and is reviewed elsewhere [13,14]. In this review, we focus on the enzymology of protein Spalmitoylation, its relationship to cancer, and the potential of the enzymes involved as therapeutic targets. We begin with a brief summary of the functional consequences of protein S-palmitoylation to provide the cellular context where acylating and deacylating enzymes reside, then review the structure and mechanism of DHHC palmitoyltransferases, discussing the common and distinctive features of this family of 23 human enzymes. Similarly, we cover three cytoplasmic depalmitoylating enzymes, LYPLA1, LYPLA2, and LYPLAL1. The relationship of protein S-palmitoylation with cancer will be covered in three sections. Of the 23 human ZDHHC genes, at least a dozen have been implicated in cancer. The evidence for their involvement will be presented and discussed. Next, we discuss how specific palmitoylation substrates are associated with canonical and emerging hallmarks of cancer. Finally, we describe the small molecule inhibitors that have been developed for acylating and deacylating enzymes,

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Fig. 1. Structures of fatty acyl modifications of proteins. A) S-palmitoylation, thioester linkage to cysteine. B) N-myristoylation, amide linkage to N-terminal glycine; amide-linked palmitate is found on the N-terminus of hedgehog proteins. C) N-palmitoylation; amide linkage to the ε-amino group of lysine residues. D) O-palmiteoylation, oxyester linkage to serine. E) 0octanoylation; oxyester linkage to serine.

Please cite this article as: M. Yeste-Velasco, et al., Protein S-palmitoylation and cancer, Biochim. Biophys. Acta (2015), http://dx.doi.org/10.1016/ j.bbcan.2015.06.004

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Fig. 2. Membrane topology of DHHC proteins and S-palmitoylation reaction. A) Core membrane topology representation of a standard DHHC protein. DHHCs have 4 to 6 transmembrane (TM) domains with the DHHC domain and the N- and C-terminal regions in the cytosol. B) Diagram depicting protein S-palmitoylation and depalmitoylation reactions. DHHC proteins catalyze the incorporation of a 16-carbon saturated fatty acid palmitate from palmitoyl coenzyme A (PalCoA) onto a cysteine residue (Cys) through a thioester linkage. This modification is reversible. Lysophospholipases (LYPLAs) with acylprotein thiosterase activity catalyze the hydrolysis of palmitic acid (palCOOH) from palmitoylated proteins.

discuss their effectiveness, and issues that need further study to determine if targeting protein S-palmitoylation will be a feasible strategy for therapeutic intervention in cancer.

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2. Overview of the functional consequences of protein S-palmitoylation

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S-palmitoylation can control protein functionality in many different ways. For soluble proteins, a primary function of protein palmitoylation

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Fig. 3. Palmitoylated proteins involved in cancer. Diagram showing a summary of the palmitoylated proteins involved in the regulation of four hallmarks of cancer and the enabling characteristic tumor-promoting inflammation. There is no general pattern for increased or decreased palmitoylation of the listed proteins except in angiogenesis where all the listed proteins have increased palmitoylation in cancer.

is to mediate membrane attachment. As mentioned above, numerous palmitoylated signaling proteins are first modified with a prenyl or Nmyristoyl group, followed by S-palmitoylation. The addition of the first lipid promotes transient membrane interactions and the protein will sample various endomembrane compartments until it is palmitoylated by a membrane-associated palmitoyltransferase. The addition of the second lipid inhibits membrane dissociation, a process known as kinetic trapping [15]. G-protein α subunits of the Gi family are examples of proteins modified sequentially by myristate and palmitate, whereas H-, N-, and K-Ras4a proteins are modified sequentially by a farnesyl isoprenoid and palmitate [6]. The reversibility of S-palmitoylation enables cycles of acylation and deacylation to regulate the trafficking of peripheral membrane proteins [5]. This is best exemplified from studies of the trafficking of the oncogenic proteins H-Ras and N-Ras. S-palmitoylation occurs on the Golgi apparatus, stabilizing Ras association with membranes. Trafficking of the S-palmitoylated proteins to the plasma membrane occurs by vesicular transport. Depalmitoylation leads to release of the protein followed by diffusion-mediated movement to endomembranes until the protein is kinetically trapped again at the Golgi apparatus by palmitoylation [16,17]. Interestingly, both palmitoylation-defective Ras proteins and irreversibly palmitoylated Ras proteins display the same mislocalization phenotype, driven by entropic redistribution to all endomembranes. Ras palmitoylation mutants or Ras modified with stable thioetherlinked lipids cannot be kinetically trapped at the Golgi by palmitoylation and redirected into the secretory pathway to the plasma membrane [17]. Protein S-palmitoylation also participates in the lateral organization of cellular membranes, serving as a targeting signal for lipid raft association [18]. The lipid raft hypothesis proposes that sterols, glycosphingolipids, and saturated lipids drive the formation of small and dynamic domains that co-exist with liquid-disordered regions of the membrane. Modification of proteins with longer saturated acyl chains will facilitate their

Please cite this article as: M. Yeste-Velasco, et al., Protein S-palmitoylation and cancer, Biochim. Biophys. Acta (2015), http://dx.doi.org/10.1016/ j.bbcan.2015.06.004

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3. Enzymology of protein S-palmitoylation

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3.1. DHHC palmitoyltransferases

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In 2002, the first protein acyltransferases (PATs) that modify proteins on the cytoplasmic face of membranes were identified in yeast [19,20]. Genetic and biochemical studies revealed that the PATs for Ras and yeast casein kinase 2 shared a DHHC protein domain of unknown function. An apparent variant of the C2H2 zinc finger motif, the DHHC domain is named for the highly conserved Asp-His-His-Cys sequence embedded in a cysteine-rich domain (CRD). Families of genes that encode proteins with DHHC domains are found in all eukaryotic organisms. The number of members ranges from five in the yeast Schizosaccharomyces pombe to 23 in humans, where the genes are designated ZDHHC1 to 24 without ZDHHC10. The presence of multiple family members suggests differences in substrate specificity and/or activity [21]. All DHHC proteins have a predicted core structure of four transmembrane domains with the conserved DHHC domain located on the cytoplasmic face between the second and third transmembrane domains. A few DHHC proteins contain ankyrin repeats followed by two transmembrane domains that are Nterminal to the core structure. Sequence conservation is limited to the 51-amino acid DHHC domain. The amino-terminal and carboxyterminal cytosolic domains are highly variable and may contain domains involved in protein–protein interactions, including the aforementioned ankyrin repeats, SH3 domains or PDZ-binding motifs. These variable domains are probably involved in substrate binding and contribute to protein substrate specificity [7,22]. In mammals most are localized on endomembranes, predominantly in the ER or Golgi, with only a few localized at the plasma membrane [23]. The conserved DHHC domain is essential for PAT activity, with the DHHC cysteine acting as the catalytic residue of the enzyme. DHHC proteins use a two-step kinetic mechanism [24]. First, the DHHC protein autoacylates using acyl-CoA as a donor, forming a transient acylenzyme intermediate. Second, the fatty acid is transferred to the protein substrate [25]. Although palmitate is the most abundant fatty acid attached to proteins, modification with other saturated and unsaturated long-chain fatty acids has been reported. In vitro, DHHC2 and DHHC3 proteins display different substrate specificity for acyl-CoAs, suggesting that enzyme preference for acyl-CoAs may account for the diversity of fatty acids found on proteins in cells [25]. DHHC protein substrate specificity was addressed globally by a proteomic study in yeast [26]. Single and higher order deletion of ZDHHC genes showed that some substrates were palmitoylated by several DHHC proteins, whereas a single enzyme modifies other substrates. The overlapping substrate specificity of DHHC proteins, as in yeast [26], has been confirmed in mammalian cells [27,28]. It is clear that some substrates are recruited to specific enzymes by sequences or domains within the variable N-terminal and C-terminal domains. Examples include DHHC5 and DHHC8 recruitment of their substrate GRIP1, which contains a PDZ domain that binds to the C-terminal PDZ-

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3.2. Depalmitoylating enzymes

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Only a few depalmitoylating enzymes have been identified. LYPLA1 was purified on the basis of its lysophospholipase activity, but later shown to have acylprotein thioesterase activity and named APT1 [39]. Two related enzymes are LYPLA2 (APT2) and LYPLAL1 (APTL1). These are cytoplasmic enzymes, but also localize on membranes by modification with palmitate. LYPLA1/APT1 depalmitoylates itself and LYPLA2, suggesting a regulatory mechanism for controlled access of the depalmitoylating enzymes to their substrates on cell membranes [40]. In this model, palmitoylation plays a positive regulatory role in providing access to substrates at the plasma membrane. An alternative model has been proposed that suggests cytosolic LYPLA1 is active on substrates throughout the cell. In this study, palmitoylated APT1 was found enriched on Golgi membranes. The authors proposed that autodepalmitoylation of APT1 at the Golgi prevents it from antagonizing Golgi-localized PAT activity, thereby maintaining the spatial organization of palmitoylated peripheral membrane proteins in cells [41]. The absence of consensus sequences surrounding palmitoylation sites raises questions as to the substrate specificity of LYPLA enzymes, just as it does for DHHC enzymes. Assignment of substrates to specific LYPLA enzymes has been limited to date. Palmitoylated Ras proteins are the best characterized substrates of LYPLA1 [39,42], but other substrates have been identified. GAP-43 is depalmitoylated by LYPLA1 but not LYPLA2 [43]. BK channels are depalmitoylated by LYPLA1, but not LYPLA2. The BK channel is also the first substrate reported for LYPLAL1 [44]. LYPLA1 and LYPLA2 are targets of microRNAs with important implications in chronic lymphocytic leukemia (CLL). LYPLA1 was first reported to be a target of mir138a in neurons, where it is involved in the regulation of dendritic spine morphogenesis [45]. A recent study confirms the targeting of LYPLA1 by mir138a and identified LYPLA2 as a target of mir424 [46]. In CLL, mir138a and mir424 are both downregulated.

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binding motif of each enzyme [29] and DHHC13 and DHHC17 binding to the huntingtin protein through ankyrin repeats [30]. Other DHHC proteins appear to have very broad substrate specificity. For example DHHC3 has been identified as a PAT for both peripheral and integral membrane proteins. DHHC3 resides in the Golgi apparatus, which appears to be a hub for palmitoylation of peripheral membrane proteins that cycle between endomembranes and the plasma membrane. The subcellular localization of other PATs may also contribute to substrate access. For example, DHHC2 cycles between endosomes and the plasma membrane where it palmitoylates its substrate PSD-95 [31]. In addition to their PAT activity, certain DHHC proteins can also perform palmitoylation-independent regulatory functions through protein–protein interactions. For example, DHHC17 binds to c-Jun Nterminal kinase (JNK) to form a signaling module for JNK activation [32]. Similarly, DHHC1 regulation of innate immune signaling triggered by DNA viruses is independent of its PAT activity. DHHC1 binds to MITA/ STING, promoting its aggregation and recruitment of downstream signaling components to regulate interferon expression [33]. Regulation of DHHC enzymes is an area that is ripe for further investigation. A few mechanisms have been reported. (1) The Ras PATS yeast Erf2 and mammalian DHHC9 require an associated subunit for full activity, Erf4 in yeast [19] and GCP16 in mammals [34]. Erf4 is required to stabilize the acyl–Erf2 intermediate and palmitoyl transfer to its substrate [35]. (2) microRNA regulation of ZDHHC gene expression has been reported. ZDHHC9 expression in somatostatin neurons is repressed by microRNA-134 [36] and ZDHHC1 is a predicted target for miR-93, which is downregulated in colon cancer stem cells [37]. (3) As noted above, DHHC2 access to its substrate PSD-95 is regulated by DHHC2 trafficking to the plasma membrane, which is controlled by synaptic activity [31]. (4) Finally, the activity of DHHC proteins appears to be regulated by oligomerization, with dissociation of the oligomer correlated with an increase in enzyme activity [38].

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partitioning into the liquid-ordered lipid milieu of the rafts. Interestingly, palmitoylation of both peripheral and integral membrane proteins facilitates raft association. Although there is no single unifying function for palmitoylation of membrane proteins, van der Goot and coworkers have proposed that four mechanisms likely account for most functional consequences [7]. In addition to the raft-targeting function described above, palmitoylation can induce a change in the conformation of the protein in the membrane, which may be critical for proteins to bypass quality control mechanisms and exit the ER. Palmitoylation may also impact protein–protein interactions or protein complex formation. Finally, there can be an interplay between palmitoylation and other posttranslational modifications, ubiquitination or phosphorylation. Several recent reviews on this topic are available [7,8].

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Please cite this article as: M. Yeste-Velasco, et al., Protein S-palmitoylation and cancer, Biochim. Biophys. Acta (2015), http://dx.doi.org/10.1016/ j.bbcan.2015.06.004

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4.1. DHHC2

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Several lines of evidence support a role for ZDHHC2 as a tumor suppressor. ZDHHC2 was named ream for reduced expression associated with metastasis and is located in chromosome 8p21.3–22. This region is frequently deleted or affected by loss of heterozygosity in several metastatic cancers including hepatocellular carcinoma, colorectal, breast, nonsmall cell lung, prostate, and bladder cancers [48–51]. Proliferation, migration, and invasion were inhibited in a hepatocellular carcinoma cell line overexpressing DHHC2 [49]. In addition, DHHC2 expression was significantly reduced in primary and metastatic foci of advanced colorectal cancer and in gastric cancer, where it is associated with lymph node metastasis and poor prognosis [50]. A well-described function of DHHC2 is its regulation of cytoskeletonassociated protein4 (CKAP4). CKAP4 palmitoylation by DHHC2 is required for CKAP4 trafficking from the ER to the plasma membrane, where it functions as a receptor for antiproliferative factor (APF). APF treatment of cells induces CKAP4 phosphorylation of CKAP4 and translocation to the nucleus where it binds to DNA to inhibit proliferation in bladder and cervical cancer cell lines [52–54]. Higher levels of expression of CKAP4 and ZDHHC2 were correlated with better overall survival of patients with hepatocellular carcinoma and combined may serve as useful biomarkers [50]. Other substrates of DHHC2 are tetraspanins CD9 and CD151, which are regulated by Golgi-dependent palmitoylation [55]. Complexes of tetraspanins, integrins, signaling molecules, and other proteins form tetraspanin-enriched microdomains (TEM), and regulate cell motility, morphology, fusion, proliferation and apoptosis of cells. Palmitoylation of CD9 and CD151 by DHHC2 promotes physical association between CD9 and CD151, and between alpha3 integrin and other proteins. DHHC2 stabilizes CD9 and CD151 protein stability, enabling them to evade lysosomal degradation. Knockdown of DHHC2, but not other DHHC proteins, decreases cell–cell contact in epidermoid carcinoma A431 cells [55].

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Table 1 Summary of the roles of human DHHC family members in human cancers.

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ZDHHC2 ZDHHC3 ZDHHC7 ZDHHC9 ZDHHC11 ZDHHC14 ZDHHC17 ZDHHC20 ZDHHC21

4.3. DHHC5

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Consistent with their physiological importance, abnormalities in protein palmitoylation and DHHC proteins have roles in human disease, including schizophrenia, X-linked mental retardation, and Huntington's disease [28,47]. The number of studies reporting the involvement of specific DHHC proteins in cancer has been rapidly increasing, showing the importance of this family and protein palmitoylation in tumorigenesis. In this section we will summarize the evidence for the involvement of individual DHHC proteins that are associated with cancers (Table 1).

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DHHC3 is a Golgi-localized PAT that has been linked to the palmitoylation of numerous substrates through overexpression studies and thus has the potential for involvement in the regulation of proliferation and cell death. Loss of ZDHHC3 has been reported in squamous cell cervical carcinoma [56], suggesting a potential tumor suppressive function. Potential substrates of DHHC3 that could mediate a tumor suppressor function include DR4 (TRAIL-R1), a receptor of the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Palmitoylation of DR4 targets it to the plasma membrane where it binds TRAIL to induce apoptosis, which can lead to the clearing of cancer cells. It has been shown that the TRAIL-resistant human hepatocellular carcinoma Hep3B cell line expresses high levels of DR4, but very low level of ZDHHC3. Reconstitution of ZDHHC3 expression sensitizes cells to TRAIL [57]. On the other hand, DHHC3 can be oncogenic by regulating the laminin-binding integrin α6β4, which is involved in regulating cancer cell motility and invasion through Src. The palmitoylation of α6β4 by DHHC3 is necessary for its expression, stability, and function [58].

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DHHC5 is a potential oncogenic PAT in non-small cell lung cancer (NSCLC). Knockdown of ZDHHC5 decreased cell proliferation, colony formation and invasion in NSCLC cell lines and severely inhibited xenograft tumor formation in mice [59]. Moreover, ZDHHC5 was found to be upregulated in NSCLC cell lines compared to immortalized normal human lung bronchial epithelial cell lines (HBECs). However, immunostaining of 218 clinical samples showed no correlation between DHHC5 expression and patient survival [59]. Therefore, further analysis in larger cohorts is required.

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Both tumor suppressive and oncogenic roles for ZDHHC7 have been described. ZDHHC7 is located on the long arm chromosome 16q region, whose loss is one of the earliest cytogenetic alterations in ER-positive invasive breast cancer. Whole-arm chromosome 16q losses are associated with decreased expression of candidate tumor suppressor genes in breast cancer, including ZDHHC7 [60]. DHHC7 and DHHC21 are the proteins responsible for the palmitoylation of the sex steroid estrogen, progesterone and androgen receptors (ER, PR and AR). These receptors act canonically through transcriptional gene regulation in the nucleus, but also have non-genomic functions at the plasma membrane where they activate ERK and phosphatidylinositol 3-kinase (PI3K) signaling. DHHC7- and DHHC21-dependent palmitoylation is necessary for the localization of sex steroid receptors at the plasma membrane and their ability to activate the ERK and PI3K/AKT pathways, thereby enhancing cell survival and proliferation of cancer cells [61]. These results are in

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The consequent increase in expression of LYPLA1 and LYPLA2 depalmitoylates the proapoptotic protein CD95, thereby inhibiting apoptosis.

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Expected role

Cancer type

Substrates

References

TS TS Oncogenic TS Oncogenic TS Oncogenic TS Oncogenic TS Oncogenic Oncogenic Oncogenic

Colorectal, gastric, liver, breast, non-small cell lung, prostate and bladder cancers Squamous cell cervical carcinoma N/A Breast and colorectal cancer Breast cancer Myeloma, colorectal, gastric, ovarian, breast, lung and prostate cancers Bladder and lung cancer Testis, prostate, brain, kidney, lung, ovarian, colorectal cancers and lyposarcoma Lymphoma, leukemia, gastric cancer and tongue squamous cell carcinoma Liver, pancreas, thyroid gland, bladder and vulva cancers Colon, breast, lung, prostate and gastric cancers Breast, colon, kidney, prostate and ovarian cancers Breast cancer, leukemia and lymphoma

CKAP4, CD9 and CD151 DR4 α6β4 ERβ and FasR ERα, PR, AR and NCAM H-Ras and N-Ras

[48–55] [56] [58] [60,62–64] [61,65,66] [68–72] [73,74] [80] [75–79] [85] [83–85] [86] [61,87–89]

ER, PR, AR and PECAM1/CD31

TS: tumor suppressing.

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No reports linking ZDHHC8 and tumorigenesis have appeared to date. However, it has been demonstrated that ZDHHC8 knockdown could improve the therapeutic efficacy of radiation therapy for malignant mesothelioma. The combination of ZDHHC8 siRNA and Xirradiation induces chromosomal instability and apoptosis by impairing the cell cycle G2/M checkpoint [67].

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Upregulation of ZDHHC9 has been reported in human colorectal cancer. Its expression is increased in adenocarcinoma samples compared to normal mucosa. Colorectal cancers are classified into two molecular subgroups, microsatellite stable and instable. Microsatellite instable tumors represent approximately 15% of the cases and have a better prognosis than the much larger second group, microsatellite stable tumors. ZDHHC9 overexpression is significantly higher in the stable group compared to the microsatellite instable subgroup [68]. A search of the Oncomine database (http://www.oncomine.org/resource/login.html) revealed that ZDHHC9 gene expression is upregulated in many cancers, including lung, prostate, ovarian and gastric cancers [69,70]. DHHC9's oncogenic role could be explained by its function as a palmitoyltransferase for H-Ras and N-Ras. These two Ras isoforms are palmitoylated in the Golgi compartment to facilitate their transport to the plasma membrane, where they control a wide range of signal transduction pathways critical for cell growth, differentiation and cytoskeletal remodeling. Deregulation of Ras function is a well-known mechanism of tumorigenesis. H- and N-Ras are palmitoylated by a protein complex DHHC9 and GCP16, resembling their yeast homologues Erf2 and Erf4 [34]. Genetic evidence supports the evolutionary relationship of DHHC9/ GCP16 and Erf2/Erf4, both in budding and fission yeast, as Ras PATs [70–72]. The study in fission yeast demonstrated that human DHHC9 but not the closely related DHHC14 can functionally replace Erf2. Moreover, they showed that ZDHHC9 has an oncogenic role in a premalignant breast cancer cell line (MCF10AT) [70].

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ZDHHC11 is located on the genomic region 5p15.33, which has been found to be a copy number gain region in bladder cancer, where it is strongly linked to high grade, advanced stage, and disease progression

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Alterations of ZDHHC14 in cancer suggest roles both as an oncogene and a tumor suppressor. Copy number gain of chromosome 6q25.3. which contains ZDHHC14, is present in diffuse large B-cell lymphoma [75] and in lymph node-positive cases of tongue squamous cell carcinoma (TSCC), where ZDHHC14 upregulation is associated with aggressiveness and metastasis [76]. ZDHHC14 was also found to be overexpressed in gastric cancer [77], where it is proposed to induce cell migration and invasion [78]. In acute biphenotypic leukemia and subsets of acute myeloid leukemia, a recurrent chromosomal translocation t(6;14)(q25;q32) leads to ZDHHC14 upregulation. Based on functional assays of induced ZDHHC14 overexpression in the lymphoma cell line K526, DHHC14 is proposed to inhibit leukocyte differentiation [79]. On the other hand, ZDHHC14 is underexpressed in many human cancers, including liposarcoma, brain, kidney, lung, ovarian and colorectal cancers, as revealed in the Oncomine database. In our recent study, we showed that ZDHHC14 has a tumor suppressor role in testicular germ cell tumors (TGCTs) and prostate cancer. A recurrent small deletion on 6q25.3 affecting just ZDHHC14 was found in TGCTs, which consequently leads to ZDHHC14 downregulation. ZDHHC14 was also found to be underexpressed in prostate cancer, despite the fact that less frequency of the 6q25.3 deletion was detected. In vitro functional assays have shown that ZDHHC14 heterozygous knock-out increases colony formation ability and that induced ZDHHC14 overexpression promotes apoptosis in prostate cell lines. In vivo, ZDHHC14 overexpression blocks xenograft tumor growth [80]. The apparent contradictory roles of ZDHHC14 in cancer could be due to differential substrate selection depending on the cell type and context [81]. It is also possible that DHHC14 has functions independent of PAT activity that manifest only in some cellular contexts.

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One study has shown that ZDHHC17/HIP14 acts as an oncogene. Overexpression of ZDHHC17 oncogenically transforms cells in culture and causes aggressive tumors in mice, properties that are dependent on the catalytic cysteine in the DHHC domain and thus its PAT activity [82]. The authors speculated that DHHC17/HIP14's oncogenic role could be through Ras palmitoylation, based on in vitro assays of PAT activity with farnesylated peptides. However, in other studies that have catalogued DHHC17/HIP14 substrates, Ras proteins have not been identified [83,84]. Thus, further investigation is required to find the DHHC17/HIP14 substrate that mediates its oncogenic role. A survey of human tumors indicated that ZDHHC17 is upregulated in colon, stomach, breast, lung and prostate tumors and that its expression increased with the gradation of tumor stage. However, ZDHHC17 expression is downregulated in liver, pancreas, thyroid gland, bladder, and vulva cancers. The number of samples studied was limited, so further analysis in larger cohorts is necessary [85].

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DHHC20 has been reported as a potential pro-tumorigenic PAT. NIH3T3 cells expressing ZDHHC20 in NIH3T3 cells displayed increased cellular proliferation, reduced contact inhibition, and growth in soft agar. In addition, ZDHHC20 was found to be upregulated in ovary, breast, colon, kidney and prostate tumors in comparison with organ-matched normal tissues [86], although a larger number of samples should be examined to confirm this.

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[73]. The gain of 5p15.33 is also one of the most consistent alterations in the early stages of nonsmall-cell lung cancer [74]. Both reports point towards a potential oncogenic role of ZDHHC11. However, further evaluation and functional studies are required to confirm such a role.

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conflict with the putative tumor suppressor role for ZDHHC7. However, it could be explained by the finding that another palmitoylated isoform of ER, ERβ, induces apoptotic cell death, leading to an anti-proliferative effect opposed to the positive effect promoted by ERα [62,63]. This issue will be discussed more fully in Section 6. Further support for a tumor suppressive role for ZDHHC7 comes from a study showing that DHHC7 palmitoylates the death receptor FasR. Palmitoylation mediated by DHHC7 prevents FasR degradation in lysosome, resulting in higher levels of total and cell surface FasR. Modulation of ZDHHC7 expression in colorectal cancer cells resulted in a corresponding modulation of Fas cell surface expression and sensitivity to cell death [64]. DHHC7 may promote cancer progression through its action on neural cell adhesion molecule (NCAM). NCAM is a cell surface glycoprotein that functions in neural development and synaptic plasticity. The growth factor FGF2 regulates NCAM palmitoylation, translocation to lipid rafts, and neurite outgrowth. NCAM is a substrate for DHHC7 and its activity is increased by FGF2, consistent with a positive regulatory role for DHHC7 in NCAM function [65]. NCAM is normally not expressed in ovarian epithelium, but is highly expressed in a subset of ovarian epithelial carcinomas and associated with high tumor grade. Through its interactions with the FGF receptor, NCAM facilitates EOC cell migration and invasion in vitro and promotes metastasis in mice [66].

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Hanahan and Weinberg's hallmarks of cancer provide a paradigm that encompasses the cellular properties and changes associated with tumorigenesis and metastasis [90]. Palmitoylated proteins are involved in at least four classic hallmarks of cancer: sustained proliferative signaling, resistance to cell death, induction of angiogenesis, and activation of invasion and metastasis. Evidence suggests that palmitoylated proteins also participate in the enabling characteristic of tumor-promoting inflammation. The roles of cancer-related palmitoylated proteins in tumorigenesis and metastasis, classified by their respective hallmarks, are summarized next.

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5.1. Sustained proliferative signaling

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Ras genes are the most frequently mutated family of oncogenes in human cancers [91]. Ras proteins transduce signals from growth factor receptors to intracellular effector pathways that regulate cell proliferation. Oncogenic mutations of Ras genes compromise Ras GTPase activity, which functions as a negative feedback mechanism to control proliferation. As described in Section 2, palmitoylated isoforms of Ras maintain steady state plasma membrane localization through cycles of palmitoylation and depalmitoylation [16,17], which is essential for transduction of extracellular proliferative signals [5,92]. Accordingly, inhibition of Ras plasma membrane localization has been proposed as a therapeutic strategy. Blocking the palmitoylation cycle of H-, N-, and K-Ras4a is beginning to be explored for its therapeutic potential and will be discussed in Section 7. Src-family tyrosine kinases (SFKs) participate in signaling pathways that regulate many aspects of tumorigenesis, including proliferation, survival, angiogenesis, motility, and adhesion. The role of c-Src in cancer development has been studied most intensively and inhibitors that target SFKs are in clinical trials [93]. More limited information is available on the involvement of other SFK family members in cancers. Efficient signaling by SFKs requires association with the plasma membrane mediated by a targeting sequence that combines N-myristoylation and a second motif. c-Src uses myristate plus a polybasic sequence, whereas most other SFKs (Fyn, Lyn, Lck, Yes, and Hck) are N-myristoylated and S-palmitoylated [9]. A recent study evaluated the tumorigenic potential of all SFKs in the development of prostate cancer. Src was the most potent, followed by Fyn and Lck. Interestingly, loss of palmitoylation of Fyn accelerated tumorigenesis, whereas introduction of palmitoylation sites

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5.2. Resisting cell death

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The induction of apoptosis, a form of programmed cell death, serves as an impediment to tumor development that cancer cells must circumvent. It is known that many apoptosis regulators are regulated by palmitoylation. The most well studied cases are the extrinsic/death receptor apoptotic pathway regulators that include Fas Ligand [97] and its receptor FasR (CD95) [98,99], as well as the TRAIL receptors DR4 [57,100] and DR6 [101]. Palmitoylation of FasL is necessary for its efficient proteolytic processing by ADAM10 and its cytotoxicity [97] A common feature of FasL, FasR, and DR4 is palmitoylation-dependent localization in lipid rafts. DR6 appears to be an exception in that mutation of the palmitoylation site did not affect its raft localization [101]. In raft microdomains, the receptors form part of the death-inducing signaling complex (DISC) that activates the extrinsic apoptotic pathway. As noted in Section 4.4, palmitoylation of FasR also prevents its degradation in lysosomes [64]. Other palmitoylated receptors involved in regulating cell death are DCC (deleted in colorectal cancer) and UNC5H, which belong to the family of dependence receptors. When unoccupied by their ligand netrin-1, these receptors induce apoptosis. In the presence of ligand, the receptors inhibit apoptosis. Both receptors are putative tumor suppressors whose expression is lost in many cancer types. In the case of DCC, palmitoylation is necessary for its location in lipid rafts and essential for cell death signaling [102], whereas for UNC5H, its location in lipid rafts is not dependent on palmitoylation, but is required for its proapoptotic activity [103]. The main regulator of the intrinsic/mitochondrial apoptotic pathway BAX is also regulated by palmitoylation. BAX palmitoylation controls its translocation from the cytosol to the mitochondria, where BAX induces the permeabilization of the mitochondrial outer membrane, leading to the release of cytochrome c into cytosol and triggering apoptosis. It has been shown that ectopic expression of 12 out of the 23 ZDHHCs increase BAX palmitoylation to different extents. However, only ZDHHC3, 7, 11, 12 and 21 induce a significant increase of Bax palmitoylation and increase apoptosis levels. It has also been shown that in malignant tumor cells from Hodgkin lymphoma patients, the lack of BAX palmitoylation leads to apoptosis resistance [104]. Another protein that requires palmitoylation to induce apoptosis is Rho B, whose palmitoylation is necessary for its location in endosomes, which consequently activates apoptosis and suppresses tumor cell growth [105]. In addition, c-ABL, a non-receptor tyrosine kinase implicated in DNA damage-induced cell death, interacts with DHHC16. The pro-apoptotic activities of DHHC16 and c-abl are synergistic when coexpressed [106].

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Together with DHHC7, DHHC21 is one of the PATs responsible for sex steroid receptor palmitoylation, which mediates their association with the plasma membrane and signaling activity through ERK and PI3K/AKT pathways. In the case of the estrogen receptor, this is consistent with overexpression of ZDHHC21 in human breast cancer compared with normal breast epithelium. It is known that aggressive breast cancer or breast cancer that is resistant to endocrine therapy is sometimes associated with significantly increased ERα localization and function outside the nucleus, including at the plasma membrane [61]. Another substrate for DHHC21 is the adhesion protein, platelet endothelial cell adhesion molecule-1 (PECAM1/CD31) [87]. PECAM1/CD31 is known to inhibit apoptosis and is potentially involved in hematopoietic and vascular cancers [88]. Palmitoylation of PECAM1/CD31 is necessary for its localization in membrane subdomains and facilitates its cytoprotective activity [89]. Knockdown of ZDHHC21 inhibits PECAM1/ CD31 palmitoylation and expression levels, with a corresponding loss of cell surface expression of PECAM1/CD31 [87]. ZDHHC21 overexpression is found in leukemia and lymphoma as found in the Oncomine database, consistent with a potential role in promoting PECAM1/CD31 activity in hematopoietic cancers.

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into Src reduced its transforming potential, demonstrating that dysregulation of SFKs has an impact on their oncogenic potential [94]. The neurotensin receptor 1 (NTSR-1) is a G-protein-coupled receptor known to be a mediator of cancer progression in breast, pancreas, prostate, colon and lung cancers. NTSR-1 location in membrane microdomains and its efficient signaling depends on palmitoylation. Thus, blocking NTSR-1 palmitoylation may be a strategy to inhibit NTSR1 mitogenic signaling [95]. One of the most frequent signaling pathways mutated in cancer is the Wnt pathway, which functions to control cell proliferation, differentiation, polarity, and migration. Canonical Wnt signaling via β-catenin is transduced by the Frizzled proteins and Lipoprotein receptor-related proteins (LRP) 5 and 6. LRP6 is palmitoylated, a modification that is required for LRP6 to exit from the endoplasmic reticulum and transit to the cell surface. Interestingly, there is an interaction between palmitoylation and ubiquitination of LRP6 at the plasma membrane that is required for efficient Wnt signaling. The mechanism is unknown, but the authors speculate that palmitoylation of LRP6 may enable it to interact with another palmitoylated protein, casein kinase 1γ, which acts as a cytoplasmic signal transducer for LRP6 [96].

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To grow and develop, tumors require a supply of nutrients and oxygen and must evacuate metabolic wastes and carbon dioxide. Both needs are met by the generation of tumor-associated neovasculature, a cancer hallmark known as angiogenesis. The palmitoylation-regulated integrin α6β4 [58] and tetraspanins CD9 and CD151 [110], in addition to their roles in cell migration and invasion, are also involved in promoting angiogenesis. CD9 and CD151 knock-out mice present reduced growth of implanted tumors, which is accompanied by decreased angiogenesis [110]. Other palmitoylated proteins with a pro-angiogenic role are endothelial nitric oxide synthase (eNOS) and platelet-activating factor acetylhydrolase IB subunit gamma (PAFAH1b3). Evidence suggests that eNOS promotes angiogenesis and tumorigenesis [118,119]. eNOS can be palmitoylated by several DHHCs, with DHHC21 having the greatest effect on its localization in the Golgi complex and cholesterolrich microdomains of the plasma membrane [120]. Finally, plateletactivating factor acetylhydrolase IB subunit gamma (PAFAH1b3) has been shown to be palmitoylated upon insulin stimulation. Chemical inhibition of palmitoylation prevented insulin-induced angiogenesis and reduced cell migration in vitro. Knockdown of PAFAH1b3 had the same effect as chemical inhibition [121].

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The cause of death in most cancer cases is metastasis, the spread of cancer from the original site to other parts of the body. Metastasis is the result of a multistep process, beginning with the invasion of cancers cancer into neighboring tissue, followed by intravasation into nearby blood and/or lymphatic vessels, transit through the circulation, extravasation into distant tissues, formation of small nodules of cancer cells (micrometastases) and finally growth into macroscopic tumors. During each of these steps, cancer cells develop alterations in their shape, attachment to other cells, and interactions with the extracellular matrix (ECM) [90]. Many palmitoylated proteins are involved in regulating the invasion and metastasis hallmark. As described in Section 4.1, tetraspanins and their associated proteins are important regulators of cell morphology, adhesion, motility, and proliferation. Several tetraspanins are regulated by palmitoylation, which facilitates their organization in TEMs and interactions with neighboring proteins. Tumor suppressive activities linked to invasion and metastasis are associated with KAT1/CD82 and CD9. Palmitoylation of KAT1/CD82 facilitates its inhibition of migration and invasion of PC-3 prostate cancer cells [108,109]. In combination with the presence of α4 integrin ligands, CD82 palmitoylation supports increased molecular density of α4 integrins within membrane clusters, thereby promoting cellular adhesion [108,109]. Similarly, palmitoylation of CD9 and CD151 by DHHC2 increases cell–cell contacts of human epidermoid carcinoma A431 cells [55], consistent with DHHC2's presumptive function as a tumor suppressor. Whereas CD9 is typically linked with suppression of metastasis, in vivo studies suggest that CD151 promotes metastasis [110]. CD151 activates α3β1 integrin-dependent tumor cell adhesion and migration [111]. Several members of the integrin family or proteins are regulated by palmitoylation. Integrins are transmembrane receptors involved in cell– cell and cell–extracellular matrix interactions. Once triggered, integrins activate signal transduction to regulate cell shape and motility, among other cellular functions. To date, it is known that integrins subunits α3, α6, α7 and β4 are palmitoylated [112]. It has been shown that the laminin-binding integrin α6β4, after being palmitoylated by DHHC3, activates Src to induce cell motility and invasion [58]. CDCP1, a protein with oncogenic functions in several cancers, is degraded upon palmitoylation, leading to a decrease of ovarian cancer cell migration [113]. The small GTPase Rac1 has an important role in cytoskeletal reorganization and cell migration. Palmitoylation targets Rac1 to cholesterol-rich membrane microdomains to initiate spreading and migration [114]. Other palmitoylated proteins may be involved in downregulating invasion and metastasis. The cell surface glycoprotein CD44 is targeted to lipid rafts by palmitoylation. Palmitoylation levels of CD44 and its lipid raft association are correlated with reduced breast cancer cell migration. Palmitoylation-defective CD44 localized in non-raft domains and displayed reduced interaction with pro-migratory cytoplasmic proteins, suggesting a possible mechanism by which palmitoylation negatively regulates cell migration [115]. A second example is RGS4, which inhibits breast cancer migration and metastasis through its attenuation of signaling through Gi-coupled receptors. The expression level of RGS4 is an indicator of breast cancer invasiveness [116]. Palmitoylation of

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RGS4 protects it from proteasomal degradation, thereby enhancing its 693 ability to counteract signals that promote migration [117]. 694

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5.5. Induction of Inflammation, an enabling hallmark

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Inflammation primes the microenvironment to support tumor growth and metastasis, and is thus considered an enabling hallmark of cancer. A recent study demonstrates a novel role for palmitoylated proteins in triggering the secretion of pro-inflammatory cytokines from tumor-associated macrophages (TAMs) [122]. Evidence suggests that proteins on the surface of exosomes initiate a signaling pathway that is dependent upon the Toll-Like Receptor 2 (TLR2) and NF-kB activation. Guided by the knowledge that most ligands for TLR2 are lipid-modified, the authors demonstrated that blocking palmitoylation of proteins on the exosome surface diminished activation of NFkB. Mass spectrometry of the exosomes derived from breast cancer cells revealed enrichment of a number of palmitoylated proteins, including N-Ras, transferrin receptor protein-1, and CD44. Although the authors were unable to identify a specific palmitoylated protein that promotes NF-kB activation, this study suggests that targeting protein palmitoylation may be a mechanism to block activation of TAMs and their tumor-promoting effects [122]. The pro-inflammatory cytokine TNFα is unusual in that it is fatty acylated at both cysteine residues and lysine residues in the N-terminal cytoplasmic domain. TNFα is synthesized as a transmembrane protein and trafficked to the plasma membrane where it is cleaved by an extracellular protease to release the soluble cytokine. A recent study demonstrates that S-palmitoylation of TNFα does not significantly impact cleavage of the ectodomain to generate soluble TNFα. Instead palmitoylation of membrane-bound TNFα appears to affect the function of the TNF receptor, making it less responsive to autocrine signaling by soluble TNFα [123]. Lysine fatty acylation of TNFα in the N-terminal domain was first reported in 1992 [124], but the significance of this modification has only recently been revealed [11]. SIRT6, a member of the sirtuin family, has weak deacetylase activity, but robustly removes lysine-linked fatty acids from proteins, including TNFα. TNFα secretion is reduced in SIRT6 knockout cells, suggesting that removal of lysine fatty acylation is a novel regulatory mechanism to regulate secretion. A final example of a protein involved in the regulation of inflammation is protease-activated receptor-2 (PAR2), a G-protein coupled receptor. In prostate cancer cell lines, palmitoylation of PAR2 is required

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Finally, LAT2 (linker for activation of T-cell family member 2) is a lipid raft adaptor protein for AKT signaling, which controls cell proliferation and survival in B lymphocytes and myeloid cells. Palmitoylation controls LAT2 lipid raft localization, and thus its function. The antileukemic effects of alkylphospholipids in NB4 promyelocytic leukemia cells are mediated at least in part by triggering apoptosis through the disruption of lipid rafts and a corresponding loss of LAT2 function. Accordingly, LAT2 was proposed as a potential therapeutic target [107]. Inhibition of LAT2 palmitoylation is a possible strategy to counteract LAT2's positive effects on cell proliferation and survival.

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Sex steroid receptors are involved in the development of breast and prostate cancers. As described in Sections 4.4 and 4.11, receptors for estrogen, progesterone, and androgens have non-genomic functions at the plasma membrane in addition to their role as transcriptional regulators in the nucleus. Palmitoylation targets the receptors to the plasma membrane where they mediate rapid signal transduction events in response to ligand binding [126,127]. DHHC7 and DHHC21 catalyze the palmitoylation of the estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR) at a highly conserved cysteine within the ligand-binding domain [61]. ERα and ERβ are encoded by separate genes and have opposing roles in controlling cellular proliferation. For both proteins, their location and interaction with other proteins within plasma membrane subdomains are regulated by cycles of palmitoylation and depalmitoylation. Nongenomic functions of ErRα are positive regulators of cellular proliferation. ERα that is localized at the plasma membrane is associated with caveolin-1. Upon stimulation with the primary female sex hormone 17β-estradiol (E2), ERα undergoes depalmitoylation and dissociates from caveolin-1, which facilitates ERα association with Src kinase and activation of ERK and PI3K signaling cascades that lead to cell proliferation. Palmitoylation is essential for E2-induced rapid signaling, since palmitoylation-defective ERα does not induce ligand-stimulated proliferation [62,63]. Similarly, it has been shown that another isoform of ERα, ERα36, mediates rapid, non-genomic, membrane-associated anti-apoptotic effects in several cancer cell lines, including triple negative HCC38 breast cancer cells. Chemical inhibition of palmitoylation disrupted plasma membrane localization and the signaling activity of ERα36 [128]. An interesting molecule to modulate ERα palmitoylation is the plant-derived flavonoid naringenin (Nar), which has been shown to inhibit estrogen-stimulated cell proliferation. Nar increases the kinetics of ERα depalmitoylation, which results in more rapid dissociation of the receptor from caveolin-1. ERα binding to Src is attenuated, thereby avoiding the activation of proliferation signaling cascades. Nar also induces the ER-dependent, but palmitoylation-independent, activation of p38 kinase, which in turn is responsible for Nar-mediated antiproliferative effects in cancer cells [129]. Regulation of ERβ palmitoylation is associated with antiproliferative effects. E2 increases the association of ERβ with caveolin-1 and activates p38 kinase, which in turn triggers a downstream pro-apoptotic caspase cascade [62,63]. Estrogen receptors also function in non-reproductive tissues; ERβ is the predominant ER isoform in human colon. Loss of ERβ is associated with the advanced stages of colon cancer. Two reports have shown that palmitoylation of ERβ has proapoptotic, and thus antiproliferative, effects on colon cancer cell lines [130,131]. The progesterone receptor is another sex steroid receptor involved in inducing proliferation of breast cancer cells. Palmitoylation of PR is regulated similarly to ER [126]. Knockdown of ZDHHC7 and ZDHHC21 prevented PR palmitoylation and membrane localization. Consequently, progesterone signaling through ERK and PI3K was inhibited and the effect of progesterone on cell viability and proliferation was diminished [61]. Finally, the androgen receptor responds to the principal male sex hormones testosterone and dihydrotestosterone, playing a paramount role in prostate cancer progression. Similarly to ER and PR, the localization of AR in the plasma membrane is dependent on its palmitoylation by DHHC7 and 21, which triggers signaling that induces cell proliferation [61,126]. Hormonal therapy is the standard treatment for advanced prostate cancer. However, in most of the cases, it eventually leads to the development of castration-resistant prostate cancer, i.e., insensitive to anti-androgen treatments. It has been shown that a novel AR splice

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As discussed in the previous sections, many proteins with important roles in cancer are regulated by palmitoylation, raising the possibility of therapeutic strategies targeting this modification. Enzymes represent one of the largest classes of drug targets and are amenable to small molecule inhibition due to their structural determinants. Lipid modifications have been investigated as possible anticancer therapies. Farnesyl transferase inhibitors (FTIs) were developed as a mechanism to block oncogenic Ras association with the plasma membrane, thereby blocking access to effector molecules [9]. However, these compounds were ineffective in clinical trials, at least in part due to alternative prenylation of oncogenic Ras. FTIs are still under consideration as potential therapies for progeria and a number of other disorders. The growing association of DHHC PATs with various cancers and the finding that inhibition of LYPLA1/APT1 perturbs Ras function suggests that these enzymes may be potential therapeutic targets for cancer treatment. In this last section, we discuss the current status of small molecule inhibitors of palmitoylation and depalmitoylation and outline the issues that require further study to determine if targeting protein S-palmitoylation is a feasible strategy for treating cancer.

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Currently two types of small molecule inhibitors of palmitoylation are available: lipid-based and non-lipid based. The first group includes 2bromopalmitate (2-BP), cerulenin, and tunicamycin. All three compounds inhibit palmitoylation of proteins in cells, but lack specificity. The most commonly used is 2-BP, which inhibits palmitoylation of proteins in cells, but also inhibits a number of enzymes involved in lipid metabolism, including fatty acid CoA ligase, carnitine palmitoyltransferase 1, glycerol3-phosphate acyltransferase and enzymes in the synthesis of triacylglycerol biosynthesis [133]. 2-BP directly and irreversibly inhibits DHHC PATs by blocking formation of the acyl-enzyme intermediate [134]. Analogs of 2-BP modified with an alkyl group to enable detection using click chemistry have been used as activity-based chemical probes to profile DHHC PATs and other enzymes in cells [135,136]. These compounds label DHHC proteins but not a catalytically inactive mutant, suggesting that alkylation is occurring at the active site cysteine of the DHHC motif. However, numerous other proteins in cells are also labeled by the 2-BP analogs, including many known palmitoylation substrates. Thus, 2-BP can inhibit protein palmitoylation by inactivation of DHHC enzymes or through direct alkylation of palmitoylated proteins in cells [135]. The natural antibiotic cerulenin inhibits palmitoylation of a number of substrates in cells, including palmitoylated Ras isoforms. It has been proposed that cerulenin blocks palmitoylation by alkylating cysteine residues in DHHC proteins or their substrates. Like 2-BP, cerulenin also affects cellular lipid metabolism, mainly by inhibiting fatty acid synthases. Interest in development of cerulenin analogs that were more selective for palmitoylation inhibition was driven by the finding that cerulenin inhibits the proliferation of Ras-transformed cells, including T24 bladder carcinoma cells that overexpress H-ras. A compound that displayed the

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variant, AR8, which is up-regulated in castration-resistant prostate cancer cells, lacks a DNA binding domain. Although only a fraction of most steroid hormone receptors are membrane-associated, AR8 is predominately localized at the plasma membrane, presumably through palmitoylation of two cysteine residues within its unique C-terminus. In prostate cancer cells, AR8 facilitate association of Src and AR with the EGF receptor in response to EGF treatment, enhancing tyrosine phosphorylation of AR by Src and promoting cell proliferation and survival. The cysteine residues of AR8 are essential for its plasma membrane location and function, suggesting that targeting palmitoylation is a potential strategy for treating castration-resistant prostate cancers associated with AR8 expression [132].

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for trafficking of the receptor from the Golgi to the plasma membrane [125].

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Depalmitoylation is an enzyme-regulated process, which opens a new avenue to control protein palmitoylation. Attention to this arm of the palmitoylation cycle has been focused on LYPLA1 and its effects on the intracellular localization and activity of Ras proteins. Chemical inhibition of LYPLA1 results in a redistribution of Ras to endomembranes and attenuation of signaling. Using a structure-guided computational strategy, Waldmann and coworkers developed a LYPLA1 inhibitor built on a β-lactone core called palmostatin B. The compound inhibits LYPLA1 by rapidly forming an ester bond with the nucleophilic serine in the active site of the enzyme, with slow reactivation of the enzyme upon hydrolysis of the compound. Palmostatin B caused H-Ras specific delocalization from the plasma membrane to endomembranes, whereas K-Ras 4B (nonpalmitoylated) was not affected [42]. In hematopoietic cells expressing oncogenic N-Ras and treated with Palmostatin B, cytokine-independent colony formation was inhibited and accompanied by mislocalization of Ras [143]. A second compound, Palmostatin M, is similar to Palmostatin B with respect to inhibition of LYPLA1 enzyme activity in vitro, but is a more potent inhibitor of Ras localization and functions in cells [144]. Activity-based protein profiling with palmostatin analogs demonstrates that the palmostatins target LYPLA1 and LYPLA2 in cells, as well as the lysosomal acyl protein thioesterase PPT1 and a number of other proteins [145]. In an effort to identify inhibitors that are selective for LYPLA1 or LYPLA2, a competitive activity-based protein profiling method was used to screen a large (315,004) library of compounds. This study identified individual piperazine amides that selectively and reversibly inhibited LYPLA1 or LYPLA2 [146,147]. Selectivity for their respective targets was confirmed in vivo. These compounds will be important tools to interrogate the specific functions of LYPLA1 and LYPLA2 in cells and animal models. Boronic and borinic acid derivatives represent another class of LYPLA1 and LYPLA2 inhibitors identified in a high throughput screen for compounds that bind to the enzymes. One of the compounds displayed competitive inhibition of both LYPLA1 and LYPLA2 in vitro and inhibited signaling through MAP kinase in MDCK cells expressing a constitutively active H/N Ras. These results confirm the involvement of LYPLA1/LYPLA2 in Ras signaling and underscore the potential of depalmitoylation inhibitors as a novel therapeutic strategy for Rasdriven cancers [148]. Lysine fatty acylation represents a novel area for development of small molecule inhibitors. Although the mechanism of fatty acid addition to lysine on proteins is unknown, there is substantial evidence that members of the sirtuin family are de-fatty acylases [11,12,149]. The diverse biological functions of sirtuins and their well characterized role as deacetlyases has led to the development of Inhibitors of sirtuins, some of which have anti-cancer activity [150]. It will be interesting to determine how existing and newly developed inhibitors impact lysine fatty acylation in cells and the corresponding biological consequences. In order to avoid a lack of specificity and potentially undesirable effects due to DHHC and LYPLA substrate promiscuity, efforts should be directed that specifically target enzyme–substrate interactions. A good example is a study where it was found that depalmitoylation of H-

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However, it is clear that drug discovery programs for protein kinases have identified ATP substrate analogs that are highly selective for individual protein kinases [133]. Identifying allosteric inhibitors that target regions distant from the active site may also be useful. Targeting the enzyme:substrate interaction sites found in unique regions of DHHC proteins may yield molecules that specifically inhibit palmitoylation of a substrate of interest [28]. It should be feasible to develop high throughput assays of substrate palmitoylation by specific DHHC proteins, as has been done with the Hedgehog acyltransferase, the MBOAT protein that palmitoylates the secreted morphogen hedgehog [142].

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appropriate selectivity for inhibition of palmitoylation vs. fatty acid synthase was identified. However, further drug development was not feasible due to the hydrophobicity of the compound and the reactivity of the epoxycarboxamide moiety [137]. A more recent study used a “clickable” cerulenin analog as a probe for protein palmitoylation in cells. The cerulenin analog effectively detected DHHC PATs and identified over 200 proteins as putative cellular targets. In contrast to 2-BP, the cerulenin analog modified DHHC proteins in which the catalytic cysteine was mutated. The ability to detect catalytically inactive DHHC may have utility in characterizing DHHC proteins in various disease models [138]. The nucleoside antibiotic tunicamycin, which is primarily known as an inhibitor of protein N-linked glycosylation, is also a lipid-based palmitoylation inhibitor. Although its palmitoylation inhibitory mechanism is still undetermined, it has been suggested that it competes with palmitoyl-CoA for binding to palmitoyltransferases [139]. Discovery and development of lipid-based inhibitors poses several challenges due to their poor solubility. In high throughput screening for DHHC PAT inhibitors, biochemical assays may be preferable to those that are cell-based because the biochemical assays tolerate higher concentrations of organic solvents used to solubilize library compounds. Other considerations are that poor solubility of potential therapeutics increases the risk of toxicity and limits bioavailability. Recent advances in the development of nanodelivery systems for lipophilic drugs show promise in alleviating these issues [140]. In addition to the lipid-based inhibitors of palmitoylation, Ducker et al. identified several non-lipid inhibitors using three cell-based assays [85]. The compounds identified in the screen segregated into five chemotypes. Representative compounds from each chemotype displayed selective inhibition of PAT activity assayed in cell membranes. Compounds I to IV inhibited palmitoylation of farnesylated peptides, whereas compound V inhibited myristoylpeptide palmitoylation. This specificity suggests that the compounds may be acting as peptide substrate competitors rather than palmitoyl-CoA competitors. Moreover all of the compounds abrogated signaling through the Raf/Mek signaling pathway in murine and human mammary adenocarcinoma cell lines. Compounds I to IV showed antitumor activity in vivo in Balb/c mice bearing tumors derived from JC cells. Compound V was not included in the in vivo experiment, since it was moderately toxic for the animals, as detected by loss of body weight and poor coat appearance [85]. Linder's group tested four of these compounds, I, II, III, and V, for direct inhibition of PAT activity using four purified DHHC proteins and their cognate farnesylated or N-myristoylated substrates. Compounds I, II and III did not significantly inhibit the DHHC proteins tested, whereas Compound V inhibited all four DHHC proteins, but did not display any preference for N-myristoylated substrates. Compound V blocked DHHC autoacylation, which, in contrast to 2BP, was reversible. Both compound V and 2BP displayed slow time-dependent inhibition, also known as slow-binding inhibition, an advantage in a pharmacological setting for long period enzyme inhibition [134]. In a separate study, cerulenin, compound V, and 2-BP were tested as competitors for labeling of DHHC4 in cells with the activity-based 2-BP analog. Only cerulenin and 2-BP competed in a dose-dependent manner. The authors suggested that, given the reversibility of Compound V, it may not be able to displace the 2-BP analog [136]. There is a need for potent and selective inhibitors of DHHC proteins to establish the feasibility of the enzymes as drug targets. This will require assays that can be adapted to a high throughput format. A fluorescence-based in vitro assay has been developed that monitors autoacylation of DHHC proteins, enabling identification of compounds that directly target the enzyme [141]. Activity-based profiling with the 2-BP analog represents a second mechanism for high throughput screening of compounds that can compete for binding [135,136]. A potential disadvantage of these approaches is that they address autoacylation, a reaction step that is common to all DHHC proteins. The high degree of homology in the active site of DHHC proteins may make it difficult to develop highly specific, active-site inhibitors.

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Conflict of interest

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The authors declare that there is no conflict of interest. Acknowledgments

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[1] B.R. Martin, C. Wang, A. Adibekian, S.E. Tully, B.F. Cravatt, Global profiling of dynamic protein palmitoylation, Nat. Methods 9 (2012) 84–89. [2] L. Dowal, W. Yang, M.R. Freeman, H. Steen, R. Flaumenhaft, Proteomic analysis of palmitoylated platelet proteins, Blood 118 (2011) e62–e73. [3] R. Kang, J. Wan, P. Arstikaitis, H. Takahashi, K. Huang, A.O. Bailey, J.X. Thompson, A.F. Roth, R.C. Drisdel, R. Mastro, W.N. Green, J.R. Yates 3rd, N.G. Davis, A. ElHusseini, Neural palmitoyl-proteomics reveals dynamic synaptic palmitoylation, Nature 456 (2008) 904–909. [4] W. Yang, D. Di Vizio, M. Kirchner, H. Steen, M.R. Freeman, Proteome scale characterization of human S-acylated proteins in lipid raft-enriched and non-raft membranes, Mol. Cell. Proteomics 9 (2010) 54–70. [5] M. Schmick, A. Kraemer, P.I. Bastiaens, Ras moves to stay in place, Trends Cell Biol. 25 (2015) 190–197. [6] J.E. Smotrys, M.E. Linder, Palmitoylation of intracellular signaling proteins: regulation and function, Annu. Rev. Biochem. 73 (2004) 559–587. [7] S. Blaskovic, M. Blanc, F.G. van der Goot, What does S-palmitoylation do to membrane proteins? FEBS J. 280 (2013) 2766–2774. [8] M.J. Shipston, Ion channel regulation by protein S-acylation, J. Gen. Physiol. 143 (2014) 659–678. [9] M.D. Resh, Targeting protein lipidation in disease, Trends Mol. Med. 18 (2012) 206–214.

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References

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We thank Martin Ian Malgapo for providing Fig. 1. YJL and MY acknowledge funding support from Orchid and Association for International Cancer Research (Grant No: 09-0512) and MEL acknowledges 1049 Q7 research support from Cornell University. 1047 1048

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In the past few years, major advances have been made in the identification of DHHC protein acyltransferases, their substrates and the functional consequences of protein palmitoylation. Many studies have shown that deregulation of DHHC proteins and protein palmitoylation is involved in human disease, highlighting the physiological importance of this family of proteins. One of the most exciting areas in the field is the involvement of the enzymes that mediate reversible protein palmitoylation in human cancers, as described in this review. We anticipate that many more associations will be reported in future years. Our current knowledge must be extended before it can be translated into novel cancer therapies. First, we must have a deeper understanding of how palmitoylation functions to regulate cancer pathways in relevant cell and animal models. Small molecules that modulate DHHC PATs and depalmitoylating enzymes will be important tools to advance these lines of research. Second, a link between protein palmitoylation and a specific type of human cancer must be validated. This can be achieved with animal models, e.g., humanized xenograft models or transgenic animals, and demonstration of a strong association in human clinical samples. Third, extensive functional and structural studies of the enzymes and their substrates are required to develop drugs that specifically target their interaction. This must be combined with high throughput screening and efforts at rational drug design to identify and develop small molecules that modulate the relevant enzymes. We envision that success with these endeavors will lead to clinical trials of compounds that target protein palmitoylation.

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[10] J.F. Hancock, A.I. Magee, J.E. Childs, C.J. Marshall, All Ras proteins are polyisoprenylated but only some are palmitoylated, Cell 57 (1989) 1167–1177. [11] H. Jiang, S. Khan, Y. Wang, G. Charron, B. He, C. Sebastian, J. Du, R. Kim, E. Ge, R. Mostoslavsky, H.C. Hang, Q. Hao, H. Lin, SIRT6 regulates TNF-alpha secretion through hydrolysis of long-chain fatty acyl lysine, Nature 496 (2013) 110–113. [12] Z. Liu, T. Yang, X. Li, T. Peng, H.C. Hang, X.D. Li, Integrative chemical biology approaches for identification and characterization of “erasers” for fatty-acid-acylated lysine residues within proteins, Angew. Chem. 54 (2015) 1149–1152. [13] S.C. Chang, A.I. Magee, Acyltransferases for secreted signalling proteins (review), Mol. Membr. Biol. 26 (2009) 104–113. [14] J.A. Buglino, M.D. Resh, Palmitoylation of Hedgehog proteins, Vitam. Horm. 88 (2012) 229–252. [15] H. Schroeder, R. Leventis, S. Rex, M. Schelhaas, E. Nagele, H. Waldmann, J.R. Silvius, S-acylation and plasma membrane targeting of the farnesylated carboxyl-terminal peptide of N-ras in mammalian fibroblasts, Biochemistry 36 (1997) 13102–13109. [16] J.S. Goodwin, K.R. Drake, C. Rogers, L. Wright, J. Lippincott-Schwartz, M.R. Philips, A.K. Kenworthy, Depalmitoylated Ras traffics to and from the Golgi complex via a nonvesicular pathway, J. Cell Biol. 170 (2005) 261–272. [17] O. Rocks, A. Peyker, M. Kahms, P.J. Verveer, C. Koerner, M. Lumbierres, J. Kuhlmann, H. Waldmann, A. Wittinghofer, P.I.H. Bastiaens, An acylation cycle regulates localization and activity of palmitoylated Ras isoforms, Science 307 (2005) 1746–1752. [18] I. Levental, M. Grzybek, K. Simons, Greasing their way: lipid modifications determine protein association with membrane rafts, Biochemistry 49 (2010) 6305–6316. [19] S. Lobo, W.K. Greentree, M.E. Linder, R.J. Deschenes, Identification of a Ras palmitoyltransferase in Saccharomyces cerevisiae, J. Biol. Chem. 277 (2002) 41268–41273. [20] A.F. Roth, Y. Feng, L. Chen, N.G. Davis, The yeast DHHC cysteine-rich domain protein Akr1p is a palmitoyl transferase, J. Cell Biol. 159 (2002) 23–28. [21] S. Blaskovic, A. Adibekian, M. Blanc, G.F. van der Goot, Mechanistic effects of protein palmitoylation and the cellular consequences thereof, Chem. Phys. Lipids (2014). [22] G.M. Thomas, T. Hayashi, Smarter neuronal signaling complexes from existing components: how regulatory modifications were acquired during animal evolution: evolution of palmitoylation-dependent regulation of AMPA-type ionotropic glutamate receptors, Bioessays 35 (2013) 929–939. [23] Y. Ohno, A. Kihara, T. Sano, Y. Igarashi, Intracellular localization and tissue-specific distribution of human and yeast DHHC cysteine-rich domain-containing proteins, Biochim. Biophys. Acta 1761 (2006) 474–483. [24] D.A. Mitchell, G. Mitchell, Y. Ling, C. Budde, R.J. Deschenes, Mutational analysis of Saccharomyces cerevisiae Erf2 reveals a two-step reaction mechanism for protein palmitoylation by DHHC enzymes, J. Biol. Chem. 285 (2010) 38104–38114. [25] B.C. Jennings, M.E. Linder, DHHC protein S-acyltransferases use similar ping-pong kinetic mechanisms but display different acyl-CoA specificities, J. Biol. Chem. 287 (2012) 7236–7245. [26] A.F. Roth, J. Wan, A.O. Bailey, B. Sun, J.A. Kuchar, W.N. Green, B.S. Phinney, J.R. Yates 3rd, N.G. Davis, Global analysis of protein palmitoylation in yeast, Cell 125 (2006) 1003–1013. [27] M. Fukata, Y. Fukata, H. Adesnik, R.A. Nicoll, D.S. Bredt, Identification of PSD-95 palmitoylating enzymes, Neuron 44 (2004) 987–996. [28] J. Greaves, L.H. Chamberlain, DHHC palmitoyl transferases: substrate interactions and (patho)physiology, Trends Biochem. Sci. 36 (2011) 245–253. [29] G.M. Thomas, T. Hayashi, S.L. Chiu, C.M. Chen, R.L. Huganir, Palmitoylation by DHHC5/8 targets GRIP1 to dendritic endosomes to regulate AMPA-R trafficking, Neuron 73 (2012) 482–496. [30] K. Huang, S. Sanders, R. Singaraja, P. Orban, T. Cijsouw, P. Arstikaitis, A. Yanai, M.R. Hayden, A. El-Husseini, Neuronal palmitoyl acyl transferases exhibit distinct substrate specificity, FASEB J. 23 (2009) 2605–2615. [31] Y. Fukata, A. Dimitrov, G. Boncompain, O. Vielemeyer, F. Perez, M. Fukata, Local palmitoylation cycles define activity-regulated postsynaptic subdomains, J. Cell Biol. 202 (2013) 145–161. [32] G. Yang, M.S. Cynader, Palmitoyl acyltransferase zD17 mediates neuronal responses in acute ischemic brain injury by regulating JNK activation in a signaling module, J. Neurosci. 31 (2011) 11980–11991. [33] Q. Zhou, H. Lin, S. Wang, S. Wang, Y. Ran, Y. Liu, W. Ye, X. Xiong, B. Zhong, H.B. Shu, Y.Y. Wang, The ER-associated protein ZDHHC1 is a positive regulator of DNA virustriggered, MITA/STING-dependent innate immune signaling, Cell Host Microbe 16 (2014) 450–461. [34] J.T. Swarthout, S. Lobo, L. Farh, M.R. Croke, W.K. Greentree, R.J. Deschenes, M.E. Linder, DHHC9 and GCP16 constitute a human protein fatty acyltransferase with specificity for H- and N-Ras, J. Biol. Chem. 280 (2005) 31141–31148. [35] D.A. Mitchell, L.D. Hamel, K. Ishizuka, G. Mitchell, L.M. Schaefer, R.J. Deschenes, The Erf4 subunit of the yeast Ras palmitoyl acyltransferase is required for stability of the Acyl-Erf2 intermediate and palmitoyl transfer to a Ras2 substrate, J. Biol. Chem. 287 (2012) 34337–34348. [36] S. Chai, X.A. Cambronne, S.W. Eichhorn, R.H. Goodman, MicroRNA-134 activity in somatostatin interneurons regulates H-Ras localization by repressing the palmitoylation enzyme, DHHC9, Proc. Natl. Acad. Sci. U. S. A. 110 (2013) 17898–17903. [37] X.F. Yu, J. Zou, Z.J. Bao, J. Dong, miR-93 suppresses proliferation and colony formation of human colon cancer stem cells, World J. Gastroenterol. 17 (2011) 4711–4717. [38] J. Lai, M.E. Linder, Oligomerization of DHHC protein S-acyltransferases, J. Biol. Chem. 288 (2013) 22862–22870.

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and N-Ras is accelerated by binding of the prolyl isomerase FKBP12. Treatment of cells with the FKBP12 inhibitor FK506 increased the steady-state levels of palmitoylated H-Ras, preventing relocalization of H-Ras to the Golgi and enhancing Ras signaling [151]. This example underscores that knowledge of specific enzyme–substrate interactions will be essential for the development of effective anticancer therapies that target DHHC proteins and depalmitoylating enzymes.

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F

[63] M. Marino, P. Ascenzi, Membrane association of estrogen receptor alpha and beta influences 17beta-estradiol-mediated cancer cell proliferation, Steroids 73 (2008) 853–858. [64] A. Rossin, J. Durivault, T. Chakhtoura-Feghali, N. Lounnas, L. Gagnoux-Palacios, A.O. Hueber, Fas palmitoylation by the palmitoyl acyltransferase DHHC7 regulates Fas stability, Cell Death Differ. (2014). [65] E. Ponimaskin, G. Dityateva, M.O. Ruonala, M. Fukata, Y. Fukata, F. Kobe, F.S. Wouters, M. Delling, D.S. Bredt, M. Schachner, A. Dityatev, Fibroblast growth factor-regulated palmitoylation of the neural cell adhesion molecule determines neuronal morphogenesis, J. Neurosci. 28 (2008) 8897–8907. [66] S. Zecchini, U. Cavallaro, Neural cell adhesion molecule in cancer: expression and mechanisms, Adv. Exp. Med. Biol. 663 (2010) 319–333. [67] H. Sudo, A.B. Tsuji, A. Sugyo, Y. Ogawa, M. Sagara, T. Saga, ZDHHC8 knockdown enhances radiosensitivity and suppresses tumor growth in a mesothelioma mouse model, Cancer Sci. 103 (2012) 203–209. [68] F. Mansilla, K. Birkenkamp-Demtroder, M. Kruhoffer, F.B. Sorensen, C.L. Andersen, P. Laiho, L.A. Aaltonen, H.W. Verspaget, T.F. Orntoft, Differential expression of DHHC9 in microsatellite stable and instable human colorectal cancer subgroups, Br. J. Cancer 96 (2007) 1896–1903. [69] S. Meng, F.L. Zhou, W.G. Zhang, X.M. Cao, B.Y. Wang, Y. Wang, G.G. Bai, The research on the expression and localization of multiple myeloma associated antigen MMSA-1, Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 28 (2012) 63–66. [70] E. Young, Z.Y. Zheng, A.D. Wilkins, H.T. Jeong, M. Li, O. Lichtarge, E.C. Chang, Regulation of Ras localization and cell transformation by evolutionarily conserved palmitoyltransferases, Mol. Cell. Biol. 34 (2014) 374–385. [71] D.A. Mitchell, L.D. Hamel, K.D. Reddy, L. Farh, L.M. Rettew, P.R. Sanchez, R.J. Deschenes, Mutations in the X-linked intellectual disability gene, zDHHC9, alter autopalmitoylation activity by distinct mechanisms, J. Biol. Chem. 289 (2014) 18582–18592. [72] M.M. Zhang, P.Y. Wu, F.D. Kelly, P. Nurse, H.C. Hang, Quantitative control of protein S-palmitoylation regulates meiotic entry in fission yeast, PLoS Biol. 11 (2013) e1001597. [73] Y. Yamamoto, Y. Chochi, H. Matsuyama, S. Eguchi, S. Kawauchi, T. Furuya, A. Oga, J.J. Kang, K. Naito, K. Sasaki, Gain of 5p15.33 is associated with progression of bladder cancer, Oncology 72 (2007) 132–138. [74] J.U. Kang, S.H. Koo, K.C. Kwon, J.W. Park, J.M. Kim, Gain at chromosomal region 5p15.33, containing TERT, is the most frequent genetic event in early stages of non-small cell lung cancer, Cancer Genet. Cytogenet. 182 (2008) 1–11. [75] A. Rinaldi, I. Kwee, G. Poretti, A. Mensah, G. Pruneri, D. Capello, D. Rossi, E. Zucca, M. Ponzoni, C. Catapano, M.G. Tibiletti, M. Paulli, G. Gaidano, F. Bertoni, Comparative genome-wide profiling of post-transplant lymphoproliferative disorders and diffuse large B-cell lymphomas, Br. J. Haematol. 134 (2006) 27–36. [76] T. Onda, N. Yamamoto, T. Yakushiji, R. Takagi, I. Kamiyama, T. Uchiyama, N. Takano, T. Shibahara, Aberrant expression of ZDHHC14 gene in human tongue squamous cell carcinoma, EJC Suppl. 7 (2009) 148-148. [77] K. Anami, N. Oue, T. Noguchi, N. Sakamoto, K. Sentani, T. Hayashi, T. Hinoi, M. Okajima, J.M. Graff, W. Yasui, Search for transmembrane protein in gastric cancer by the Escherichia coli ampicillin secretion trap: expression of DSC2 in gastric cancer with intestinal phenotype, J. Pathol. 221 (2010) 275–284. [78] H.Z. Oo, K. Sentani, N. Sakamoto, K. Anami, Y. Naito, N. Uraoka, T. Oshima, K. Yanagihara, N. Oue, W. Yasui, Overexpression of ZDHHC14 promotes migration and invasion of scirrhous type gastric cancer, Oncol. Rep. 32 (2014) 403–410. [79] L. Yu, J.C. Reader, C. Chen, X.F. Zhao, J.S. Ha, C. Lee, T. York, I. Gojo, M.R. Baer, Y. Ning, Activation of a novel palmitoyltransferase ZDHHC14 in acute biphenotypic leukemia and subsets of acute myeloid leukemia, Leukemia 25 (2011) 367–371. [80] M. Yeste-Velasco, X. Mao, R. Grose, S.C. Kudahetti, D. Lin, J. Marzec, N. Vasiljevic, T. Chaplin, L. Xue, M. Xu, J.M. Foster, S.S. Karnam, S.Y. James, A.M. Chioni, D. Gould, A.T. Lorincz, R.T. Oliver, C. Chelala, G.M. Thomas, J.M. Shipley, S.J. Mather, D.M. Berney, B.D. Young, Y.J. Lu, Identification of ZDHHC14 as a novel human tumour suppressor gene, J. Pathol. 232 (2014) 566–577. [81] J. Greaves, L.H. Chamberlain, New links between S-acylation and cancer, J. Pathol. 233 (2014) 4–6. [82] C.E. Ducker, E.M. Stettler, K.J. French, J.J. Upson, C.D. Smith, Huntingtin interacting protein 14 is an oncogenic human protein: palmitoyl acyltransferase, Oncogene 23 (2004) 9230–9237. [83] K. Huang, A. Yanai, R. Kang, P. Arstikaitis, R.R. Singaraja, M. Metzler, A. Mullard, B. Haigh, C. Gauthier-Campbell, C.A. Gutekunst, M.R. Hayden, A. El-Husseini, Huntingtin-interacting protein HIP14 is a palmitoyl transferase involved in palmitoylation and trafficking of multiple neuronal proteins, Neuron 44 (2004) 977–986. [84] S.L. Butland, S.S. Sanders, M.E. Schmidt, S.P. Riechers, D.T. Lin, D.D. Martin, K. Vaid, R.K. Graham, R.R. Singaraja, E.E. Wanker, E. Conibear, M.R. Hayden, The palmitoyl acyltransferase HIP14 shares a high proportion of interactors with huntingtin: implications for a role in the pathogenesis of Huntington's disease, Hum. Mol. Genet. 23 (2014) 4142–4160. [85] C.E. Ducker, L.K. Griffel, R.A. Smith, S.N. Keller, Y. Zhuang, Z. Xia, J.D. Diller, C.D. Smith, Discovery and characterization of inhibitors of human palmitoyl acyltransferases, Mol. Cancer Ther. 5 (2006) 1647–1659. [86] J.M. Draper, C.D. Smith, DHHC20: a human palmitoyl acyltransferase that causes cellular transformation, Mol. Membr. Biol. 27 (2010) 123–136. [87] E.P. Marin, B. Derakhshan, T.T. Lam, A. Davalos, W.C. Sessa, Endothelial cell palmitoylproteomic identifies novel lipid-modified targets and potential substrates for protein acyl transferases, Circ. Res. 110 (2012) 1336–1344. [88] C. Bergom, C. Gao, P.J. Newman, Mechanisms of PECAM-1-mediated cytoprotection and implications for cancer cell survival, Leuk. Lymphoma 46 (2005) 1409–1421.

N

C

O

R

R

E

C

T

[39] J.A. Duncan, A.G. Gilman, A cytoplasmic acyl-protein thioesterase that removes palmitate from G protein alpha subunits and p21(RAS), J. Biol. Chem. 273 (1998) 15830–15837. [40] E. Kong, S. Peng, G. Chandra, C. Sarkar, Z. Zhang, M.B. Bagh, A.B. Mukherjee, Dynamic palmitoylation links cytosol-membrane shuttling of acyl-protein thioesterase-1 and acyl-protein thioesterase-2 with that of proto-oncogene H-ras product and growth-associated protein-43, J. Biol. Chem. 288 (2013) 9112–9125. [41] N. Vartak, B. Papke, H.E. Grecco, L. Rossmannek, H. Waldmann, C. Hedberg, P.I. Bastiaens, The autodepalmitoylating activity of APT maintains the spatial organization of palmitoylated membrane proteins, Biophys. J. 106 (2014) 93–105. [42] F.J. Dekker, O. Rocks, N. Vartak, S. Menninger, C. Hedberg, R. Balamurugan, S. Wetzel, S. Renner, M. Gerauer, B. Scholermann, M. Rusch, J.W. Kramer, D. Rauh, G.W. Coates, L. Brunsveld, P.I. Bastiaens, H. Waldmann, Small-molecule inhibition of APT1 affects Ras localization and signaling, Nat. Chem. Biol. 6 (2010) 449–456. [43] V.M. Tomatis, A. Trenchi, G.A. Gomez, J.L. Daniotti, Acyl-protein thioesterase 2 catalyzes the deacylation of peripheral membrane-associated GAP-43, PLoS One 5 (2010) e15045. [44] L. Tian, H. McClafferty, H.G. Knaus, P. Ruth, M.J. Shipston, Distinct acyl protein transferases and thioesterases control surface expression of calcium-activated potassium channels, J. Biol. Chem. 287 (2012) 14718–14725. [45] G. Siegel, G. Obernosterer, R. Fiore, M. Oehmen, S. Bicker, M. Christensen, S. Khudayberdiev, P.F. Leuschner, C.J. Busch, C. Kane, K. Hubel, F. Dekker, C. Hedberg, B. Rengarajan, C. Drepper, H. Waldmann, S. Kauppinen, M.E. Greenberg, A. Draguhn, M. Rehmsmeier, J. Martinez, G.M. Schratt, A functional screen implicates microRNA-138-dependent regulation of the depalmitoylation enzyme APT1 in dendritic spine morphogenesis, Nat. Cell Biol. 11 (2009) 705–716. [46] V. Berg, M. Rusch, N. Vartak, C. Jungst, A. Schauss, H. Waldmann, C. Hedberg, C.P. Pallasch, P.I. Bastiaens, M. Hallek, C.M. Wendtner, L.P. Frenzel, miRs-138 and -424 control palmitoylation-dependent CD95-mediated cell death by targeting acyl protein thioesterases 1 and 2 in chronic lymphocytic leukemia, Blood (2015). [47] F.B. Young, S.L. Butland, S.S. Sanders, L.M. Sutton, M.R. Hayden, Putting proteins in their place: palmitoylation in Huntington disease and other neuropsychiatric diseases, Prog. Neurobiol. 97 (2012) 220–238. [48] T. Oyama, Y. Miyoshi, K. Koyama, H. Nakagawa, T. Yamori, T. Ito, H. Matsuda, H. Arakawa, Y. Nakamura, Isolation of a novel gene on 8p21.3–22 whose expression is reduced significantly in human colorectal cancers with liver metastasis, Gene Chromosome Cancer 29 (2000) 9–15. [49] C. Peng, Z. Zhang, J. Wu, Z. Lv, J. Tang, H. Xie, L. Zhou, S. Zheng, A critical role for ZDHHC2 in metastasis and recurrence in human hepatocellular carcinoma, Biomed. Res. Int. 2014 (2014) 832712. [50] S.X. Li, G.S. Tang, D.X. Zhou, Y.F. Pan, Y.X. Tan, J. Zhang, B. Zhang, Z.W. Ding, L.J. Liu, T.Y. Jiang, H.P. Hu, L.W. Dong, H.Y. Wang, Prognostic significance of cytoskeletonassociated membrane protein 4 and its palmitoyl acyltransferase DHHC2 in hepatocellular carcinoma, Cancer 120 (2014) 1520–1531. [51] S.M. Yan, J.J. Tang, C.Y. Huang, S.Y. Xi, M.Y. Huang, J.Z. Liang, Y.X. Jiang, Y.H. Li, Z.W. Zhou, I. Ernberg, Q.L. Wu, Z.M. Du, Reduced expression of ZDHHC2 is associated with lymph node metastasis and poor prognosis in gastric adenocarcinoma, PLoS One 8 (2013) e56366. [52] S.L. Planey, S.K. Keay, C.O. Zhang, D.A. Zacharias, Palmitoylation of cytoskeleton associated protein 4 by DHHC2 regulates antiproliferative factor-mediated signaling, Mol. Biol. Cell 20 (2009) 1454–1463. [53] D.A. Zacharias, M. Mullen, S.L. Planey, Antiproliferative factor-induced changes in phosphorylation and palmitoylation of cytoskeleton-associated protein-4 regulate its nuclear translocation and DNA binding, Int. J. Cell Biol. 2012 (2012) 150918. [54] J. Zhang, S.L. Planey, C. Ceballos, S.M. Stevens Jr., S.K. Keay, D.A. Zacharias, Identification of CKAP4/p63 as a major substrate of the palmitoyl acyltransferase DHHC2, a putative tumor suppressor, using a novel proteomics method, Mol. Cell. Proteomics 7 (2008) 1378–1388. [55] C. Sharma, X.H. Yang, M.E. Hemler, DHHC2 affects palmitoylation, stability, and functions of tetraspanins CD9 and CD151, Mol. Biol. Cell 19 (2008) 3415–3425. [56] Y.W. Choi, S.M. Bae, Y.W. Kim, H.N. Lee, Y.W. Kim, T.C. Park, D.Y. Ro, J.C. Shin, S.J. Shin, J.S. Seo, W.S. Ahn, Gene expression profiles in squamous cell cervical carcinoma using array-based comparative genomic hybridization analysis, Int. J. Gynecol. Cancer 17 (2007) 687–696. [57] Y. Oh, Y.J. Jeon, G.S. Hong, I. Kim, H.N. Woo, Y.K. Jung, Regulation in the targeting of TRAIL receptor 1 to cell surface via GODZ for TRAIL sensitivity in tumor cells, Cell Death Differ. 19 (2012) 1196–1207. [58] C. Sharma, I. Rabinovitz, M.E. Hemler, Palmitoylation by DHHC3 is critical for the function, expression, and stability of integrin alpha6beta4, Cell Mol. Life Sci. 69 (2012) 2233–2244. [59] H. Tian, J.Y. Lu, C. Shao, K.E. Huffman, R.M. Carstens, J.E. Larsen, L. Girard, H. Liu, J. Rodriguez-Canales, E.P. Frenkel, I.I. Wistuba, J.D. Minna, S.L. Hofmann, Systematic siRNA screen unmasks NSCLC growth dependence by palmitoyltransferase DHHC5, Mol. Cancer Res. (2015). [60] D. Hungermann, H. Schmidt, R. Natrajan, N. Tidow, K. Poos, J.S. Reis-Filho, B. Brandt, H. Buerger, E. Korsching, Influence of whole arm loss of chromosome 16q on gene expression patterns in oestrogen receptor-positive, invasive breast cancer, J. Pathol. 224 (2011) 517–528. [61] A. Pedram, M. Razandi, R.J. Deschenes, E.R. Levin, DHHC-7 and -21 are palmitoylacyltransferases for sex steroid receptors, Mol. Biol. Cell 23 (2012) 188–199. [62] M. Le Romancer, C. Poulard, P. Cohen, S. Sentis, J.M. Renoir, L. Corbo, Cracking the estrogen receptor's posttranslational code in breast tumors, Endocr. Rev. 32 (2011) 597–622.

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[116] Y. Xie, D.W. Wolff, T. Wei, B. Wang, C. Deng, J.K. Kirui, H. Jiang, J. Qin, P.W. Abel, Y. Tu, Breast cancer migration and invasion depend on proteasome degradation of regulator of G-protein signaling 4, Cancer Res. 69 (2009) 5743–5751. [117] J. Wang, Y. Xie, D.W. Wolff, P.W. Abel, Y. Tu, DHHC protein-dependent palmitoylation protects regulator of G-protein signaling 4 from proteasome degradation, FEBS Lett. 584 (2010) 4570–4574. [118] X. Wei, J.G. Schneider, S.M. Shenouda, A. Lee, D.A. Towler, M.V. Chakravarthy, J.A. Vita, C.F. Semenkovich, De novo lipogenesis maintains vascular homeostasis through endothelial nitric-oxide synthase (eNOS) palmitoylation, J. Biol. Chem. 286 (2011) 2933–2945. [119] L. Ying, L.J. Hofseth, An emerging role for endothelial nitric oxide synthase in chronic inflammation and cancer, Cancer Res. 67 (2007) 1407–1410. [120] C. Fernandez-Hernando, M. Fukata, P.N. Bernatchez, Y. Fukata, M.I. Lin, D.S. Bredt, W.C. Sessa, Identification of Golgi-localized acyl transferases that palmitoylate and regulate endothelial nitric oxide synthase, J. Cell Biol. 174 (2006) 369–377. [121] X. Wei, H. Song, C.F. Semenkovich, Insulin-regulated protein palmitoylation impacts endothelial cell function, Arterioscler. Thromb. Vasc. Biol. 34 (2014) 346–354. [122] A. Chow, W. Zhou, L. Liu, M.Y. Fong, J. Champer, D. Van Haute, A.R. Chin, X. Ren, B.G. Gugiu, Z. Meng, W. Huang, V. Ngo, M. Kortylewski, S.E. Wang, Macrophage immunomodulation by breast cancer-derived exosomes requires Toll-like receptor 2-mediated activation of NF-kappaB, Sci. Rep. 4 (2014) 5750. [123] M. Poggi, I. Kara, J.M. Brunel, J.F. Landrier, R. Govers, B. Bonardo, R. Fluhrer, C. Haass, M.C. Alessi, F. Peiretti, Palmitoylation of TNF alpha is involved in the regulation of TNF receptor 1 signalling, Biochim. Biophys. Acta 1833 (2013) 602–612. [124] F.T. Stevenson, S.L. Bursten, R.M. Locksley, D.H. Lovett, Myristyl acylation of the tumor necrosis factor alpha precursor on specific lysine residues, J. Exp. Med. 176 (1992) 1053–1062. [125] M.N. Adams, M.E. Christensen, Y. He, N.J. Waterhouse, J.D. Hooper, The role of palmitoylation in signalling, cellular trafficking and plasma membrane localization of protease-activated receptor-2, PLoS One 6 (2011) e28018. [126] A. Pedram, M. Razandi, R.C. Sainson, J.K. Kim, C.C. Hughes, E.R. Levin, A conserved mechanism for steroid receptor translocation to the plasma membrane, J. Biol. Chem. 282 (2007) 22278–22288. [127] A. Pedram, M. Razandi, D. Lubahn, J. Liu, M. Vannan, E.R. Levin, Estrogen inhibits cardiac hypertrophy: role of estrogen receptor-beta to inhibit calcineurin, Endocrinology 149 (2008) 3361–3369. [128] R.A. Chaudhri, A. Hadadi, K.S. Lobachev, Z. Schwartz, B.D. Boyan, Estrogen receptoralpha 36 mediates the anti-apoptotic effect of estradiol in triple negative breast cancer cells via a membrane-associated mechanism, Biochim. Biophys. Acta (2014). [129] P. Galluzzo, P. Ascenzi, P. Bulzomi, M. Marino, The nutritional flavanone naringenin triggers antiestrogenic effects by regulating estrogen receptor alphapalmitoylation, Endocrinology 149 (2008) 2567–2575. [130] F. Caiazza, P. Galluzzo, S. Lorenzetti, M. Marino, 17Beta-estradiol induces ERbeta up-regulation via p38/MAPK activation in colon cancer cells, Biochem. Biophys. Res. Commun. 359 (2007) 102–107. [131] P. Galluzzo, F. Caiazza, S. Moreno, M. Marino, Role of ERbeta palmitoylation in the inhibition of human colon cancer cell proliferation, Endocr. Relat. Cancer 14 (2007) 153–167. [132] X. Yang, Z. Guo, F. Sun, W. Li, A. Alfano, H. Shimelis, M. Chen, A.M. Brodie, H. Chen, Z. Xiao, T.D. Veenstra, Y. Qiu, Novel membrane-associated androgen receptor splice variant potentiates proliferative and survival responses in prostate cancer cells, J. Biol. Chem. 286 (2011) 36152–36160. [133] S.L. Planey, D.A. Zacharias, Identification of targets and inhibitors of protein palmitoylation, Expert Opin. Drug Discov. 5 (2010) 155–164. [134] B.C. Jennings, M.J. Nadolski, Y. Ling, M.B. Baker, M.L. Harrison, R.J. Deschenes, M.E. Linder, 2-Bromopalmitate and 2-(2-hydroxy-5-nitro-benzylidene)benzo[b]thiophen-3-one inhibit DHHC-mediated palmitoylation in vitro, J. Lipid Res. 50 (2009) 233–242. [135] D. Davda, M.A. El Azzouny, C.T. Tom, J.L. Hernandez, J.D. Majmudar, R.T. Kennedy, B.R. Martin, Profiling targets of the irreversible palmitoylation inhibitor 2bromopalmitate, ACS Chem. Biol. 8 (2013) 1912–1917. [136] B. Zheng, M. DeRan, X. Li, X. Liao, M. Fukata, X. Wu, 2-Bromopalmitate analogues as activity-based probes to explore palmitoyl acyltransferases, J. Am. Chem. Soc. 135 (2013) 7082–7085. [137] J.M. Draper, C.D. Smith, Palmitoyl acyltransferase assays and inhibitors (review), Mol. Membr. Biol. 26 (2009) 5–13. [138] B. Zheng, S. Zhu, X. Wu, Clickable analogue of cerulenin as chemical probe to explore protein palmitoylation, ACS Chem. Biol. 10 (2015) 115–121. [139] S.I. Patterson, J.H. Skene, Novel inhibitory action of tunicamycin homologues suggests a role for dynamic protein fatty acylation in growth cone-mediated neurite extension, J. Cell Biol. 124 (1994) 521–536. [140] M. Narvekar, H.Y. Xue, J.Y. Eoh, H.L. Wong, Nanocarrier for poorly water-soluble anticancer drugs—barriers of translation and solutions, AAPS PharmSciTech 15 (2014) 822–833. [141] L.D. Hamel, R.J. Deschenes, D.A. Mitchell, A fluorescence-based assay to monitor autopalmitoylation of zDHHC proteins applicable to high-throughput screening, Anal. Biochem. 460 (2014) 1–8. [142] E. Petrova, J. Rios-Esteves, O. Ouerfelli, J.F. Glickman, M.D. Resh, Inhibitors of Hedgehog acyltransferase block Sonic Hedgehog signaling, Nat. Chem. Biol. 9 (2013) 247–249. [143] J. Xu, C. Hedberg, F.J. Dekker, Q. Li, K.M. Haigis, E. Hwang, H. Waldmann, K. Shannon, Inhibiting the palmitoylation/depalmitoylation cycle selectively reduces the growth of hematopoietic cells expressing oncogenic Nras, Blood 119 (2012) 1032–1035.

E

T

[89] C.T. Sardjono, S.N. Harbour, J.C. Yip, C. Paddock, S. Tridandapani, P.J. Newman, D.E. Jackson, Palmitoylation at Cys595 is essential for PECAM-1 localisation into membrane microdomains and for efficient PECAM-1-mediated cytoprotection, Thromb. Haemost. 96 (2006) 756–766. [90] D. Hanahan, R.A. Weinberg, Hallmarks of cancer: the next generation, Cell 144 (2011) 646–674. [91] A.G. Stephen, D. Esposito, R.K. Bagni, F. McCormick, Dragging ras back in the ring, Cancer Cell 25 (2014) 272–281. [92] B.M. Willumsen, A.D. Cox, P.A. Solski, C.J. Der, J.E. Buss, Novel determinants of HRas plasma membrane localization and transformation, Oncogene 13 (1996) 1901–1909. [93] A. Aleshin, R.S. Finn, SRC: a century of science brought to the clinic, Neoplasia 12 (2010) 599–607. [94] H. Cai, D.A. Smith, S. Memarzadeh, C.A. Lowell, J.A. Cooper, O.N. Witte, Differential transformation capacity of Src family kinases during the initiation of prostate cancer, Proc. Natl. Acad. Sci. U. S. A. 108 (2011) 6579–6584. [95] Y. Heakal, M.P. Woll, T. Fox, K. Seaton, R. Levenson, M. Kester, Neurotensin receptor-1 inducible palmitoylation is required for efficient receptor-mediated mitogenic-signaling within structured membrane microdomains, Cancer Biol. Ther. 12 (2011) 427–435. [96] L. Abrami, B. Kunz, I. Iacovache, F.G. van der Goot, Palmitoylation and ubiquitination regulate exit of the Wnt signaling protein LRP6 from the endoplasmic reticulum, Proc. Natl. Acad. Sci. U. S. A. 105 (2008) 5384–5389. [97] F. Guardiola-Serrano, A. Rossin, N. Cahuzac, K. Luckerath, I. Melzer, S. Mailfert, D. Marguet, M. Zornig, A.O. Hueber, Palmitoylation of human FasL modulates its cell death-inducing function, Cell Death Dis. 1 (2010) e88. [98] K. Chakrabandhu, Z. Herincs, S. Huault, B. Dost, L. Peng, F. Conchonaud, D. Marguet, H.T. He, A.O. Hueber, Palmitoylation is required for efficient Fas cell death signaling, EMBO J. 26 (2007) 209–220. [99] C. Feig, V. Tchikov, S. Schutze, M.E. Peter, Palmitoylation of CD95 facilitates formation of SDS-stable receptor aggregates that initiate apoptosis signaling, EMBO J. 26 (2007) 221–231. [100] A. Rossin, M. Derouet, F. Abdel-Sater, A.O. Hueber, Palmitoylation of the TRAIL receptor DR4 confers an efficient TRAIL-induced cell death signalling, Biochem. J. 419 (2009) 185–192 (182 pp. following 192). [101] M. Klima, J. Zajedova, L. Doubravska, L. Andera, Functional analysis of the posttranslational modifications of the death receptor 6, Biochim. Biophys. Acta 1793 (2009) 1579–1587. [102] C. Furne, V. Corset, Z. Herincs, N. Cahuzac, A.O. Hueber, P. Mehlen, The dependence receptor DCC requires lipid raft localization for cell death signaling, Proc. Natl. Acad. Sci. U. S. A. 103 (2006) 4128–4133. [103] C. Maisse, A. Rossin, N. Cahuzac, A. Paradisi, C. Klein, M.L. Haillot, Z. Herincs, P. Mehlen, A.O. Hueber, Lipid raft localization and palmitoylation: identification of two requirements for cell death induction by the tumor suppressors UNC5H, Exp. Cell Res. 314 (2008) 2544–2552. [104] M. Frohlich, B. Dejanovic, H. Kashkar, G. Schwarz, S. Nussberger, S-palmitoylation represents a novel mechanism regulating the mitochondrial targeting of BAX and initiation of apoptosis, Cell Death Dis. 5 (2014) e1057. [105] D.A. Wang, S.M. Sebti, Palmitoylated cysteine 192 is required for RhoB tumorsuppressive and apoptotic activities, J. Biol. Chem. 280 (2005) 19243–19249. [106] B. Li, F. Cong, C.P. Tan, S.X. Wang, S.P. Goff, Aph2, a protein with a zf-DHHC motif, interacts with c-Abl and has pro-apoptotic activity, J. Biol. Chem. 277 (2002) 28870–28876. [107] C.H. Thome, G.A. dos Santos, G.A. Ferreira, P.S. Scheucher, C. Izumi, A.M. Leopoldino, A.M. Simao, P. Ciancaglini, K.T. de Oliveira, A. Chin, S.M. Hanash, R.P. Falcao, E.M. Rego, L.J. Greene, V.M. Faca, Linker for activation of T-cell family member2 (LAT2) a lipid raft adaptor protein for AKT signaling, is an early mediator of alkylphospholipid anti-leukemic activity, Mol. Cell. Proteomics 11 (2012) 1898–1912. [108] B. Zhou, L. Liu, M. Reddivari, X.A. Zhang, The palmitoylation of metastasis suppressor KAI1/CD82 is important for its motility- and invasiveness-inhibitory activity, Cancer Res. 64 (2004) 7455–7463. [109] C.M. Termini, M.L. Cotter, K.D. Marjon, T. Buranda, K.A. Lidke, J.M. Gillette, The membrane scaffold CD82 regulates cell adhesion by altering alpha4 integrin stability and molecular density, Mol. Biol. Cell 25 (2014) 1560–1573. [110] M.E. Hemler, Tetraspanin proteins promote multiple cancer stages, Nat. Rev. Cancer 14 (2014) 49–60. [111] S. Zevian, N.E. Winterwood, C.S. Stipp, Structure–function analysis of tetraspanin CD151 reveals distinct requirements for tumor cell behaviors mediated by alpha3beta1 versus alpha6beta4 integrin, J. Biol. Chem. 286 (2011) 7496–7506. [112] X. Yang, O.V. Kovalenko, W. Tang, C. Claas, C.S. Stipp, M.E. Hemler, Palmitoylation supports assembly and function of integrin–tetraspanin complexes, J. Cell Biol. 167 (2004) 1231–1240. [113] M.N. Adams, B.S. Harrington, Y. He, C.M. Davies, S.J. Wallace, N.P. Chetty, A.J. Crandon, N.B. Oliveira, C.M. Shannon, J.I. Coward, J.W. Lumley, L.C. Perrin, J.E. Armes, J.D. Hooper, EGF inhibits constitutive internalization and palmitoylationdependent degradation of membrane-spanning procancer CDCP1 promoting its availability on the cell surface, Oncogene (2014). [114] I. Navarro-Lerida, S. Sanchez-Perales, M. Calvo, C. Rentero, Y. Zheng, C. Enrich, M.A. Del Pozo, A palmitoylation switch mechanism regulates Rac1 function and membrane organization, EMBO J. 31 (2012) 534–551. [115] I.S. Babina, E.A. McSherry, S. Donatello, A.D. Hill, A.M. Hopkins, A novel mechanism of regulating breast cancer cell migration via palmitoylation-dependent alterations in the lipid raft affiliation of CD44, Breast Cancer Res. 16 (2014) R19.

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14

[148]

[149]

[150] [151]

Hodder, H. Rosen, Characterization of a Selective, Reversible Inhibitor of Lysophospholipase 1 (LYPLA1), Probe Reports from the NIH Molecular Libraries Program, Bethesda (MD), 2010. T.J. Zimmermann, M. Burger, E. Tashiro, Y. Kondoh, N.E. Martinez, K. Gormer, S. Rosin-Steiner, T. Shimizu, S. Ozaki, K. Mikoshiba, N. Watanabe, D. Hall, I.R. Vetter, H. Osada, C. Hedberg, H. Waldmann, Boron-based inhibitors of acyl protein thioesterases 1 and 2, Chembiochem 14 (2013) 115–122. J.L. Feldman, J. Baeza, J.M. Denu, Activation of the protein deacetylase SIRT6 by long-chain fatty acids and widespread deacylation by mammalian sirtuins, J. Biol. Chem. 288 (2013) 31350–31356. J. Hu, H. Jing, H. Lin, Sirtuin inhibitors as anticancer agents, Futur. Med. Chem. 6 (2014) 945–966. I.M. Ahearn, F.D. Tsai, H. Court, M. Zhou, B.C. Jennings, M. Ahmed, N. Fehrenbacher, M.E. Linder, M.R. Philips, FKBP12 binds to acylated H-ras and promotes depalmitoylation, Mol. Cell 41 (2011) 173–185.

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[144] C. Hedberg, F.J. Dekker, M. Rusch, S. Renner, S. Wetzel, N. Vartak, C. GerdingReimers, R.S. Bon, P.I. Bastiaens, H. Waldmann, Development of highly potent inhibitors of the Ras-targeting human acyl protein thioesterases based on substrate similarity design, Angew. Chem. 50 (2011) 9832–9837. [145] M. Rusch, T.J. Zimmermann, M. Burger, F.J. Dekker, K. Gormer, G. Triola, A. Brockmeyer, P. Janning, T. Bottcher, S.A. Sieber, I.R. Vetter, C. Hedberg, H. Waldmann, Identification of acyl protein thioesterases 1 and 2 as the cellular targets of the Ras-signaling modulators palmostatin B and M, Angew. Chem. 50 (2011) 9838–9842. [146] A. Adibekian, B.R. Martin, J.W. Chang, K.L. Hsu, K. Tsuboi, D.A. Bachovchin, A.E. Speers, S.J. Brown, T. Spicer, V. Fernandez-Vega, J. Ferguson, B.F. Cravatt, P. Hodder, H. Rosen, Characterization of a Selective, Reversible Inhibitor of Lysophospholipase 2 (LYPLA2), Probe Reports from the NIH Molecular Libraries Program, Bethesda (MD), 2010. [147] A. Adibekian, B.R. Martin, J.W. Chang, K.L. Hsu, K. Tsuboi, D.A. Bachovchin, A.E. Speers, S.J. Brown, T. Spicer, V. Fernandez-Vega, J. Ferguson, B.F. Cravatt, P.

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