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Tau protein and the paired helical filament of Alzheimer’s disease
Brain Research Bulletin, Vol. 50, Nos. 5/6, pp. 469 – 470, 1999 Copyright © 1999 Elsevier Science Inc. Printed in the USA. All rights reserved 0361-9230/99/$–see front matter
PII S031-9230(99)00138-0
Tau protein and the paired helical filament of Alzheimer’s disease Michel Goedert and Aaron Klug* MRC Laboratory of Molecular Biology, Cambridge, United Kingdom [Received 18 May 1999; Accepted 18 May 1999] ner [7] firmly established that the 12 kDa fragment was a fragment of human tau. The three papers published by the Cambridge group in the middle of 1988 proved that tau protein is an integral component of the PHF [4,10,11]. By 1992, additional work by ourselves and others had established that tau is the major, if not only, component of the PHF and that the latter is made of the six brain tau isoforms that we had identified and sequenced in 1989 [2,3,6]. Over the years, the relevance of tau pathology for the neurodegenerative process was repeatedly questioned. However, the discovery of tau gene mutations in familial forms of frontotemporal dementia [5,8,9], exactly 10 years after our first papers on the subject [4,10,11], proved that tau dysfunction causes neurodegeneration, with the formation of tau filaments being the likely gain of toxic function underlying all tauopathies, including Alzheimer’s disease.
In 1907, Alzheimer described the neuropathological characteristics of the disease that was subsequently named after him. Although Kidd had described the paired helical filament (PHF) as the major structural component of the neurofibrillary tangles of Alzheimer’s disease in 1963, the molecular nature of the PHF was only uncovered in the late 1980s [4,10,11]. Early immunological studies had identified several candidate molecules, but this work did not permit one to distinguish between intrinsic PHF components and material that merely adhered to the filaments or was trapped in the tangle. Moreover, the insolubility of the filamentous material precluded quantitative biochemical purification. Martin Roth had brought the tangle problem to one of us (A.K.) at the MRC Laboratory of Molecular Biology, where the following approach was developed. The PHF is biologically inert and was defined by its ultrastructural appearance, and nothing was known about its composition. Purification inevitably entails loss of morphology, rendering electron microscopy alone unsuitable for identification of an intrinsic chemical constituent of the PHF. What was required was a label that identifies both intact individual filaments in microscopy and at the same time the protein bands obtained by gel electrophoresis from successively purified tangle preparations. The protein bands could then be sequenced and this information used for the isolation of cDNA clones encoding the partial amino acid sequence. Claude Wischik used proteases to break down the insoluble tangles and he and Tony Crowther used such tangle preparations to study the structural organisation of the PHF by 3-D image reconstruction from electron micrographs [1]. In order to obtain a label for following the purification of PHF constituents, Wischik, Michal Novak, and Cesar Milstein produced monoclonal antibodies, one of which decorated individual PHFs isolated from tangle fragments in electron microscopy and also labelled a 12 kDa protein band extracted from purified PHF preparations (a second chemical label was also used by Wischik). John Walker determined the partial amino acid sequence of this band that was then used by Michel Goedert to clone and sequence cDNAs from a human brain library. The deduced amino acid sequence showed a striking repeat pattern that was unrelated to any sequence known at the time. By RNA blotting, a major 6 kb and a minor 2 kb band were observed which were similar to the pattern of tau mRNA. The publication in early 1988 of the amino acid sequence of a mouse tau isoform by Gloria Lee and Marc Kirsch-
REFERENCES 1. Crowther, R. A.; Wischik, C. M. Image reconstruction of the Alzheimer paired helical filament. EMBO J. 4:3661–3665; 1985. 2. Goedert, M.; Spillantini, M. G.; Cairns, N. J.; Crowther, R. A. Tau proteins of Alzheimer paired helical filaments: Abnormal phosphorylation of all six brain isoforms. Neuron 8:159 –168; 1992. 3. Goedert, M.; Spillantini, M. G.; Jakes, R.; Rutherford, D.; Crowther, R. A. Multiple isoforms of human microtubule-associated protein tau: Sequences and localization in neurofibrillary tangles of Alzheimer’s disease. Neuron 3:519 –526; 1989. 4. Goedert, M.; Wischik, C. M.; Crowther, R. A.; Walker, J. E.; Klug, A. Cloning and sequencing of the cDNA encoding a core protein of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4051– 4055; 1988. 5. Hutton, M.; Lendon, C. L.; Rizzu, P.; Baker, M.; Froelich, S.; Houlden, H.; Pickering-Brown, S., Chakraverty, S.; Isaacs, A.; Grover, A.; Hackett, J.; Adamson, J.; Lincoln, S.; Dickson, D.; Davies, P.; Petersen, R. C.; Stevens, M.; de Graaff, E.; Wauters, E.; van Baren, J.; Hillebrand, M.; Joosse, M.; Kwon, J. M.; Nowotny, P.; Che, L. K.; Norton, J.; Morris, J. C.; Reed, L. A.; Trojanowski, J.; Basun, H.; Lannfelt, L.; Neystat, M.; Fahn, S.; Dark, F.; Tannenberg, T.; Dodd, P. R.; Hayward, N.; Kwok, J. B. J.; Schofield, P. R.; Andreadis, A.; Snowden, J.; Craufurd, D.; Neary, D.; Owen, F.; Oostra, B. A.; Hardy, J.; Goate, A.; van Swieten, J.; Mann, D.; Lynch, T.; Heutink, P. Association of missense and 5’-splice-site mutations in tau with the inherited dementia FTDP-17. Nature 393:702–705; 1998. 6. Lee, V. M.-Y.; Balin, B. J.; Otvos, L.; Trojanowski, J. Q. A68 —a
* Address for correspondence: Professor Sir Aaron Klug, O.M., P.R.S., MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK. Fax: ⫹44-1223 213556.
469
470 major subunit of paired helical filaments and derivatized forms of normal tau. Science 251:675– 678; 1991. 7. Lee, G.; Cowan, N.; Kirschner, M. W. The primary structure and heterogeneity of tau protein from mouse brain. Science 239:285–288; 1988. 8. Poorkaj, P.; Bird, T. D.; Wijsman, E.; Nemens, E.; Garruto, R. M.; Anderson, L.; Andreadis, A.; Wiederholt, W. C.; Raskind, M.; Schellenberg, G. D. Tau is a candidate gene for chromosome 17 frontotemporal dementia. Ann. Neurol. 43:815– 825; 1998. 9. Spillantini, M. G.; Murrell, J. R.; Goedert, M.; Farlow, M. R.; Klug, A.; Ghetti, B. Mutation in the tau gene in familial multiple system
GOEDERT AND KLUG tauopathy with presenile dementia. Proc. Natl. Acad. Sci. USA 95: 7737–7741; 1998. 10. Wischik, C. M.; Novak, M.; Edwards, P. C.; Klug, A.; Tichelaar, W.; Crowther, R. A. Structural characterization of the core of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4884 – 4888; 1988. 11. Wischik, C. M.; Novak, M.; Thogersen, H. C.; Edwards, P. C.; Runswick, M. J.; Jakes, R.; Walker, J. E.; Milstein, C.; Roth, M.; Klug, A. Isolation of a fragment of tau derived from the core of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4506 – 4510; 1988.
PII S031-9230(99)00138-0
Tau protein and the paired helical filament of Alzheimer’s disease Michel Goedert and Aaron Klug* MRC Laboratory of Molecular Biology, Cambridge, United Kingdom [Received 18 May 1999; Accepted 18 May 1999] ner [7] firmly established that the 12 kDa fragment was a fragment of human tau. The three papers published by the Cambridge group in the middle of 1988 proved that tau protein is an integral component of the PHF [4,10,11]. By 1992, additional work by ourselves and others had established that tau is the major, if not only, component of the PHF and that the latter is made of the six brain tau isoforms that we had identified and sequenced in 1989 [2,3,6]. Over the years, the relevance of tau pathology for the neurodegenerative process was repeatedly questioned. However, the discovery of tau gene mutations in familial forms of frontotemporal dementia [5,8,9], exactly 10 years after our first papers on the subject [4,10,11], proved that tau dysfunction causes neurodegeneration, with the formation of tau filaments being the likely gain of toxic function underlying all tauopathies, including Alzheimer’s disease.
In 1907, Alzheimer described the neuropathological characteristics of the disease that was subsequently named after him. Although Kidd had described the paired helical filament (PHF) as the major structural component of the neurofibrillary tangles of Alzheimer’s disease in 1963, the molecular nature of the PHF was only uncovered in the late 1980s [4,10,11]. Early immunological studies had identified several candidate molecules, but this work did not permit one to distinguish between intrinsic PHF components and material that merely adhered to the filaments or was trapped in the tangle. Moreover, the insolubility of the filamentous material precluded quantitative biochemical purification. Martin Roth had brought the tangle problem to one of us (A.K.) at the MRC Laboratory of Molecular Biology, where the following approach was developed. The PHF is biologically inert and was defined by its ultrastructural appearance, and nothing was known about its composition. Purification inevitably entails loss of morphology, rendering electron microscopy alone unsuitable for identification of an intrinsic chemical constituent of the PHF. What was required was a label that identifies both intact individual filaments in microscopy and at the same time the protein bands obtained by gel electrophoresis from successively purified tangle preparations. The protein bands could then be sequenced and this information used for the isolation of cDNA clones encoding the partial amino acid sequence. Claude Wischik used proteases to break down the insoluble tangles and he and Tony Crowther used such tangle preparations to study the structural organisation of the PHF by 3-D image reconstruction from electron micrographs [1]. In order to obtain a label for following the purification of PHF constituents, Wischik, Michal Novak, and Cesar Milstein produced monoclonal antibodies, one of which decorated individual PHFs isolated from tangle fragments in electron microscopy and also labelled a 12 kDa protein band extracted from purified PHF preparations (a second chemical label was also used by Wischik). John Walker determined the partial amino acid sequence of this band that was then used by Michel Goedert to clone and sequence cDNAs from a human brain library. The deduced amino acid sequence showed a striking repeat pattern that was unrelated to any sequence known at the time. By RNA blotting, a major 6 kb and a minor 2 kb band were observed which were similar to the pattern of tau mRNA. The publication in early 1988 of the amino acid sequence of a mouse tau isoform by Gloria Lee and Marc Kirsch-
REFERENCES 1. Crowther, R. A.; Wischik, C. M. Image reconstruction of the Alzheimer paired helical filament. EMBO J. 4:3661–3665; 1985. 2. Goedert, M.; Spillantini, M. G.; Cairns, N. J.; Crowther, R. A. Tau proteins of Alzheimer paired helical filaments: Abnormal phosphorylation of all six brain isoforms. Neuron 8:159 –168; 1992. 3. Goedert, M.; Spillantini, M. G.; Jakes, R.; Rutherford, D.; Crowther, R. A. Multiple isoforms of human microtubule-associated protein tau: Sequences and localization in neurofibrillary tangles of Alzheimer’s disease. Neuron 3:519 –526; 1989. 4. Goedert, M.; Wischik, C. M.; Crowther, R. A.; Walker, J. E.; Klug, A. Cloning and sequencing of the cDNA encoding a core protein of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4051– 4055; 1988. 5. Hutton, M.; Lendon, C. L.; Rizzu, P.; Baker, M.; Froelich, S.; Houlden, H.; Pickering-Brown, S., Chakraverty, S.; Isaacs, A.; Grover, A.; Hackett, J.; Adamson, J.; Lincoln, S.; Dickson, D.; Davies, P.; Petersen, R. C.; Stevens, M.; de Graaff, E.; Wauters, E.; van Baren, J.; Hillebrand, M.; Joosse, M.; Kwon, J. M.; Nowotny, P.; Che, L. K.; Norton, J.; Morris, J. C.; Reed, L. A.; Trojanowski, J.; Basun, H.; Lannfelt, L.; Neystat, M.; Fahn, S.; Dark, F.; Tannenberg, T.; Dodd, P. R.; Hayward, N.; Kwok, J. B. J.; Schofield, P. R.; Andreadis, A.; Snowden, J.; Craufurd, D.; Neary, D.; Owen, F.; Oostra, B. A.; Hardy, J.; Goate, A.; van Swieten, J.; Mann, D.; Lynch, T.; Heutink, P. Association of missense and 5’-splice-site mutations in tau with the inherited dementia FTDP-17. Nature 393:702–705; 1998. 6. Lee, V. M.-Y.; Balin, B. J.; Otvos, L.; Trojanowski, J. Q. A68 —a
* Address for correspondence: Professor Sir Aaron Klug, O.M., P.R.S., MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK. Fax: ⫹44-1223 213556.
469
470 major subunit of paired helical filaments and derivatized forms of normal tau. Science 251:675– 678; 1991. 7. Lee, G.; Cowan, N.; Kirschner, M. W. The primary structure and heterogeneity of tau protein from mouse brain. Science 239:285–288; 1988. 8. Poorkaj, P.; Bird, T. D.; Wijsman, E.; Nemens, E.; Garruto, R. M.; Anderson, L.; Andreadis, A.; Wiederholt, W. C.; Raskind, M.; Schellenberg, G. D. Tau is a candidate gene for chromosome 17 frontotemporal dementia. Ann. Neurol. 43:815– 825; 1998. 9. Spillantini, M. G.; Murrell, J. R.; Goedert, M.; Farlow, M. R.; Klug, A.; Ghetti, B. Mutation in the tau gene in familial multiple system
GOEDERT AND KLUG tauopathy with presenile dementia. Proc. Natl. Acad. Sci. USA 95: 7737–7741; 1998. 10. Wischik, C. M.; Novak, M.; Edwards, P. C.; Klug, A.; Tichelaar, W.; Crowther, R. A. Structural characterization of the core of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4884 – 4888; 1988. 11. Wischik, C. M.; Novak, M.; Thogersen, H. C.; Edwards, P. C.; Runswick, M. J.; Jakes, R.; Walker, J. E.; Milstein, C.; Roth, M.; Klug, A. Isolation of a fragment of tau derived from the core of the paired helical filament of Alzheimer disease. Proc. Natl. Acad. Sci. USA 85:4506 – 4510; 1988.