Gene, 145(1994)279%282 0 1994 Elsevier Science B.V. All rights reserved.
279
0378-1119/94/$07.00
GENE 07948
Analysis of the 5’ flanking sequences from the human protein kinase ~58 (PITSLREPl) -encoding gene (Promoter;
cell cycle; gene regulation;
transcription
start point; apoptosis)
John Eastona,b and Vincent J. Kidd” ‘Department of Tumor Cell Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA; and bDepartment ofCell Biology, University of Alabama at Birmingham, Birmingham, AL35294, USA Received by J.A. Engler: 6 December
1993; Accepted:
31 January
1994; Received at publishers:
10 March
1994
SUMtiARY
The ~58 (PITSLREbl) protein kinase (PK) is a member of a large supergene family related to the master mitotic protein kinase, ~34”~“‘. This PK is also a member of a sub-family itself, with at least six additional related PITSLRE PK isoforms expressed by alternative splicing and promoter utilization from three duplicated genes. Minimal overproduction of the PITSLREbl PK in Chinese hamster ovary cells results in a late mitotic delay, suggesting that this PK’s function may be related to the cell cycle [Bunnell et al., Proc. Natl. Acad. Sci. USA 87 (1990) 7467-74711. Further studies using structural and functional mutants have shown that PITSLRE PKs are involved in signaling apoptosis. The gene encoding the PITSLREPl PK has previously been isolated and structurally characterized [Eipers et al., Genomics 13 (1992) 613-6211. Here we characterize the minimal essential promoter for this gene. Analysis of a 1.18-kb stretch of DNA located upstream from the PITSLREpl start codon demonstrates that significant cat gene expression can be driven by a construct containing this sequence. Deletion studies of this DNA fragment have defined a minimal promoter that extends 144 bp 5’ of the previously mapped transcription start point (tsp), and 521 bp 5’ of the start codon. This region of PITSLREjl DNA does not contain canonical TATA-box sequences or G+C-rich sequences associated with many promoters, yet it has approximately 20% of the promoting activity when compared to the SV40 early promoter. This suggests that this DNA sequence is a relatively strong basal promoter of a previously uncharacterized type.
INTRODUCTION
The ~58 PK gene encodes a member of the p34cdc2related supergene family, whose minimal overexpression leads to a late mitotic delay due to an apparent failure Correspondence to: Dr. V.J. Kidd, Department St. Jude Children’s Research TN 38105, USA. Tel. (l-901)
Hospital, 522-0469;
of Tumor
Cell Biology,
332 N. Lauderdale, Memphis, Fax (l-901) 531-2381.
Abbreviations: aa, amino acid(s); AP, alkaline phosphatase; bp, base pairs(s); CAT, Cm acetyltransferase; cat, gene encoding CAT; cdc2, cell division control gene product; Cm, chloramphenicol; ds, double strand(ed); kb, kilobase or 1000 bp; MCS, multiple cloning site(s); nt, nucleotide(s); oligo, oligodeoxyribonucleotide; ORF, open reading frame; PCR, polymerase chain reaction; PK, protein kinase(s); PK, gene encoding PK; SV40, simian virus 40; tsp, transcription start point. SSDI 0378-1119(94)00159-P
of cytokinesis 1992). Further cells expressing active p58 PK,
(Bunnell et al., 1990; Meyerson et characterization of these cells, as well structurally altered and enzymatically has demonstrated that this PK is part
al., as inof
an apoptotic signaling pathway (Lahti et al., 1994). The ability to signal apoptosis was shown to be independent of cell-cycle delay or mitotic catastrophes in these studies. The ~58 PK is also a member of a smaller sub-family of PKs, with at least six additional mRNAs and proteins generated by alternative splicing from three duplicated and linked genes (Xiang et al., 1994). In keeping with a convention established by Meyerson et al. (1992), this family of PKs has been renamed PITSLREcl, p, or y l-3 based on the single aa code of the conserved PSTAIREbox region of these protein kinases and the gene
280 -1180
ggatcccagtggccgactcccaacagagttcccggctcacacacctgcttgggtgggacgctgggaacgcaaacctgcacaccagccccggcacagaccactccacgccgctgggcctcg -1060
gcctgtgggcaggccgcctgctactgcaagggagtggcaaagcccagggccaggctgacctctggcttctagaggtgctgaggggaaatccaacctccaatagctgctcaggtgaggacg -940
ggaacccaggtgcagtcgcagctctcggcagccagcccctgccccacttcccctgcctttgtggggtgaggggaccccacccacctgttttcttgtcttttgctcgtagaccactcgata -820
ggtgccctcctcgatcctgttcaggcactggaactcctcgacgctccggc~gccctaaaaaaaaaacctatatgaggtctcagtggcc~tgcc~gctggagggagggcggcgtccgc~gg -700 cacggcacaccggcacgggcaggtgcaggcgagagccttggactgggccaggggtggagccgggagcagctcagttctttcaaagtctctttccttgcaaaaccatctgac~ctttatt~ -580 tgaaacaaaaccagtgtgaacaaaaggccatcccagccaaatacacaGa~ctcaaqcctgt~attccagcactttgggagggcaaggcaggaggattgcttgagcccaggagttcaagac -460 cagcctggccaacatagcaacactgttttctttttttctttttQagatggclgtctcgctctgtcaccc~ggct~aataca~taataaa~tctcggctcactgcaacctccacctcctcctgg -340 gttcaggcgattctcctgcctcccaatcctagtagctgagtatcaggtgagtcgcagccccaacgcacgcccggcataatttttttatttttagtcgagacgggtttcaccacgttggcc -220 aggctggtctcgaactcctgacctcaggtg~tccacccgccttcggctccc~aagcactgggaattac~ggcgtg~gccaccgcgcccggc~ccatatccattcttgggacacttgttg +1 -100 tgcttagctgaacggegcccgcatgctgtggcagcactcgccccggtgctggtctgagcag~cgcctcctttctcttgcagaagaagtaagtgaggaagaaatg
Fig. 1. Nucleotide
sequence
of the 5’ untranslated
of a 1.18-kb BumHI-XhrrI
fragment
previously
rsp (indicated
untranslated
mapped
major
that extends
region and a small portion
region and upstream
regulatory
from near the start codon
by the downward of the promoter
arrowhead).
sequences
for the human
of the PITSLREBl
protein
The bold and italicized
region. A region of dyad symmetry
sequence
is indicated
PITSLRE
13gene. Shown is the sequence
to a region located identifies
647 bp upstream
an .4/u repeat
by the horizontal
arrows
The location of oligos used for deletion analysis of this promoter are underlined below the sequence. Locations of pertinent deletion analysis of this promoter, as well as pertinent sequence numbers, are shown above the sequence. Both the sequence and that previously as previously under
reported
described
accession
(from nt - 1056 to + 1) (Eipers et al., 1992) are shown.
(Bunnell
et al.. 1990: Eipers et al., 1992). The sequence
DNA sequence
will appear
analysis
in the 5’
above the sequence.
restriction determined
was performed
in the GenBank;EMBL
from the
element
sites used for in this study
on ds DNA templates
Nucleotide
Sequence
Database
No. U03874
(PITSLRE A, B, or C) from which the mRNA is transcribed (i.e., a PITSLRE A gene transcript is designated PITSLREd ). Previously, our laboratory cloned and characterized the p58 (PITSLRE B) gene, including a portion of the putative promoter (Eipers et al., 1991; 1992). This study identified the major tsp as a region 422 nt upstream from the start codon, which includes the portion of an intact Alu-type remajor peat oriented in a 3’ to 5’ direction in the 5’ untranslated region of PZTSLREjIl (Bunnell et al., 1990; Eipers et al., 1992). The identification of multiple PITSLRE-related PK isoforms generated from three highly conserved and physically linked genes suggests that regulation of PITSLRE gene expression is most likely complex. To further understand the nature of the PZTSLRE B gene promoter and to extend our knowledge of this gene family, we undertook an analysis of this gene’s upstream region to identify the minimal essential promoter. In this study we extend the known 5’ flanking sequence of the PITSLRE B gene to a BamHI site located 1.18-kb upstream from the start codon, demonstrate promoter activity from the 5’ flanking region using a cut reporter system, and localize the minimal promoter element within the 5’ flanking sequence. Furthermore, it appears that deletion of a region between -343 and - 124 5’ of the tsp of this gene results in a twofold increase in promoter activity, suggesting that this portion of the promoter may contain sequences which normally repress transcription of the gene.
EXPERIMENTAL
AND DISCUSSION
(a) Sequence analysis of the element The region a portion
of the PITSLRE
of the 5’ upstream
BamH -1180
3
-1180
1
I
B gene corresponding region
has previously
-422
to been
ATG
+’
I
-974
t-1
-765
t-1
PITSLREblpromoter
= 200nt
1-t
-546
1-1
-377
~58-5
-377
~58-24
-377
~58-14
-377
~58-12
Fig. 2. Schematic representation of the deletion constructs used in the CAT production assays for the PITSLRE B gene promoter. Shown are schematic representations of progressively deleted PITSLRE B promoter sequence (nt - 1180 to - 377, ~58-5) cloned into the promoterless cat vector. A series of staggered 5’ to 3’ oligos located at nt -974 (~58-24) - 765 (p58-l4), and - 546 (~58-12) and a fixed oligo corresponding to the 3’ to 5’ orientation at nt -377 (p58R) were used to generate the PCR fragments used in this study. The position of the oligos depicted in this figure correspond to the underlined sequences in Fig. 1 (i.e., -974 is the corresponding nt for the first oligo sequence used to generate the corresponding construct). Also shown is the position of the first rsp(bent arrow at nt -422) relative to the translational start. All constructs were sequenced in their entirety as detailed in Fig. I.
281 reported (Eipers et al., 1992). We extended this sequence upstream from the start codon to a BamHI site at nt - 1180 to include possible transcriptional control elements (Fig. 1). This region did not contain any significant ORFs, but did contain a perfect copy of an Alu repeat element oriented in a 3’ to 5’ direction in the 5’ untranslated region of the PITSLRE B gene. A region of dyad symmetry was noted near the tsp (Fig. l), but the possible importance of this sequence feature is not clear. The PlTSLREfll promoter sequence was analyzed for the presence of any known eukaryotic transcriptional control sequences, but we could not find evidence of either TATA box or SPl-binding sequences. The absence of TATA or G + C-rich sequences from this DNA region suggests that this promoter may belong to a unique class.
activity in human HeLa cells (Gorman et al., 1982). Transfection of these constructs and analysis of their CAT production indicated that this PZTSLRE I3 gene fragment functioned as a promoter in this system (Fig. 3). To define the minimal essential promoter element, similar constructs were made in the same vectors using progressively less of the BarnHI-BglII restriction fragment, with deletions originating at the 5’ end of the fragment (Fig. 2). These constructs were generated by PCR, progressively moving the 5’ primer towards the tsp, while anchoring the 3’ primer in one location (see Figs. 1 and 2). All of
(b) Promoter activity The upstream BarnHI-BglII fragment was cloned into enhancer + cat expression vectors to determine promoter of the BamHI-BglII PITSLRE B gene deletions of this fragment as compared
Fig. 3. Promoter activity fragment and progressive
with the SV40 early promoter.
(Panel
A) CAT production
from HeLa cells transfected with the indicated constructs. of the various non-acetylated and acetylated Cm also
shown.
with
the indicated
B) AP
(Panel
activity
~58 constructs
measured
after
or controls.
co-transfection
2.0
-
BumHI-BglII
fragment
(~58-5)
was
directionally
cloned
Progressive deletions of the original BamHI-BglII fragment were made by PCR with the following oligos: hp58-5, 5’-GGGGAAGCTTAAAGGGCCTGTGT;
hp58-24,5’-GGGGAAGCTTTGGAAGAA-
hp58-14,
1.5 .Y_ 1.0 cz EE jg
5’-GGGGAAGCTTGGTGCACAGGAC-
0.5
Hind111 restriction site was introduced on the 5’ end of the hp58-(5,12,14,24), and a synthetic XbaI restriction site was introduced to 40% confluency
for cloning
purposes.
HeLa
mid, using the Ca.phosphate precipitation technique (Wigler et al., 1977). The cells were then harvested after 48 h. Cell lysate was obtained by repeated concentration
freeze-thaw cycles (Gorman et al., 1982) and the protein was determined using the Bio-Rad protein assay kit. AP
activity was measured as described by others (Berger et al., 1988; Langer et al., 1992). CAT production was assayed by measuring the conversion of [14C] Cm to its acetylated forms by using 10 pg of protein and analyzing the products by thin-layer chromatography as described by others (Gorman et al., 1982). The thin-layer plate was developed with a Molecular Dynamics 400A Phosphorimager. ImageQuant software was used to allow accurate quantitation of the Cm acetylated forms. The results of these CAT assays were then normalized to the AP results to accurately reflect transfection efficiency between different constructs. This is reported as percent acetylation.
-I
~
0
with 10 pg
of ~58-5, ~58-24, ~58-14, ~58-12, pCATcontro1, or pCATenh and 10 pg of pSEAP (Langer et al., 1992): the alkaline phosphatase control plas-
-,s=:::
q
0.0
cells were grown
(lOO-mm dish) and were then transfected
:i::l::-:-::: 95
i
4
TCAGGC; hp58-12,5’-GGAGTGCAATGGTGAGATTCTAGAGGG; hp58R, 5’-GGGTCTAGAATCTCACCATTGCACTCC. A synthetic
on the 5’ end of hp58R
chloramphenicol
+
origin
+crncmk
into
a MCS immediately upstream contains the SV40 early pro-
moter cloned into the MCS. The negative control (none) is the pCATENH vector without a promoter sequence cloned into the MCS.
TCCAACCTCCAGTAG;
+
-12 +14 -24 x+5 as"40 -Oh
bar 3, ~58-14; bar 4, ~58-24; bar 5, ~58-5; bar 6, pSV40; bar 7, enhancer. the vector pCATenh which contains from the cat gene. pCATcontrol(SV40)
mono-acetylated
B
C) Relative
CAT enzyme activity after normalization for transfection efficiency based on the results shown in panel B. (Bar 1, mock; bar 2, ~58-12; The
di-acetylated
+
measured
The locations products are
(Panel
+
,
i 10
I
w ,
20
,
30
c ,
/
40
-.
/
,
60
60
Time (min)
C
CAT As**“*
70
282 these constructs
were sequenced
that
the complete
from
the original
DNA
in their entirety
sequence
sequence
isolated
clone. We found that a construct sequences
of efficiently
activity
was approximately
BarnHI-BglII
containing
cut expression,
promoter,
an
fragment
pSEAP
Center
for information
family members. grant
GM
regarding
This research
44088-04
other
was supported
to V.J.K.,
by a Cancer
Core grant from the NIH, and by assistance
the tsp) was
the
and that its
(ALSAC).
American
Lebanese
Syrian
Associated
from
Charities
driven
and the enzyme
(Fig. 3, panel
due to CAT enzyme
was then normalized
A and
et al.. 1992)
ity assayed (Berger et al., 1988). The resulting
construct
by NIH
nt
efficiency,
gene
(Langer
with our constructs
of Cm acetylation
upstream
and J. Xiang
PITSLRE
the genomic
(Fig. 3, panels
transfection
AP-encoding
from these cells is shown
J. Lahti
to insure unaltered
twofold higher than the intact
for transient
containing
co-transfected
driving
restriction
C). To control B-actin
from
from - 546 to - 377 bp (including
capable
vector
remained
a was
activ-
AP activity
B). The percent activity
REFERENCES
by a
for each
(Fig. 3, panel C) using the
results of the AP assay (panel B). This experiment demonstrates that the minimal essential promoter responsible for producing the PZTSLREPl mRNA from the PITSLRE B gene is encoded by sequences extending from -546 to -377 bp upstream from the start codon (- 124 bp from the tsp), and that the region between - 1180 and - 546 bp upstream from the start codon (-552 to - 124 bp relative to the tsp) contains DNA sequences that may repress normal promoter function. A search of this DNA sequence against known transcriptional data bases did not reveal a match with any of the known major promoter sequences. However. a region of dyad symmetry is contained within this limited sequence (Fig. 1). These data suggest that this sequence may define a new class of basal promoter element.
Berger. .I.. Hauber. placental
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P.G.,
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B.L.. Han,
.I., Carroll,
A.J. and
Kidd,
V.J.:
Localization of the expressed human p58 protein kinase chromosomal gene to chromosome 1~36 and a highly related sequence to chromosome 15. Genomics 11 (199 I) 621-629. Eipers. P.G.. Lahti, J.M. and Kidd, V.J.: Structure the human
p%clk-I
protein
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G.,
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by the rts-2 DNA-binding
domain
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overexpression. Mol. Cell. Biol. 12 ( 1992) 5355. 5362. Meyerson, M., Enders, G.H., Wu, C.-L.. Su, L.-K., Gorka,
Wigler, M., Silverstein,
S.. Lee, L.S.. Pellicer, A., Cheng,
R.: Transfer of purified herpes virus thymidine tured mouse cells. Cell 11 (1977) 2233232. Xiang, J.. Lahti, J.M., Grenet,
The authors appreciate the help provided by Dr. M. Roussel in establishing CAT production systems, and Dr.
Kidd.
Increased expression of a 58-kDa protein kinase leads to changes in the CHO cell cycle. Proc. Natl. Acad. Sci. USA 87 (1990)
C.. Harlow, E. and Tsai. L.-H.: A family of human protein kinases. EMBO J. I I ( 1992) 2909-2917.
ACKNOWLEDGEMENTS
indical-10.
J., Easton.
by r?tyc’
C., Nelson. cdc2-related
Y.C. and Axe].
kinase
gene to cul-
J. and Kidd, V.J.: Molecular
cloning and expression of alternatively spliced kinase isoforms. J. Biol. Chem. ( 1994) in press.
PITSLRE
protein