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. 1993 Jan;12(1):365–370. doi: 10.1002/j.1460-2075.1993.tb05665.x

Molecular characterization of the minimal protease resistant tau unit of the Alzheimer's disease paired helical filament.

M Novak 1, J Kabat 1, C M Wischik 1
PMCID: PMC413214  PMID: 7679073

Abstract

The Alzheimer's disease paired helical filament (PHF), after digestion with Pronase, retains its characteristic morphological features. We term this the protease resistant core PHF. A 12 kDa tau fragment can be released from the core as an essentially pure preparation. Sequence analysis of this fragment revealed six distinct N-termini beginning in the repeat region of tau. The precise C-terminus is unknown, but the fragment is approximately 100 residues long. A monoclonal antibody, mAb 423, which recognizes the core PHF and the 12 kDa tau fragment, does not recognize normal full-length tau. We describe cDNA synthesis and expression of candidate 12 kDa tau analogues which permit the mapping of the mAb 423 epitope. mAb 423 recognizes all and only those analogues which terminate at Glu391, which lies beyond the homology repeat region. Addition or removal of a single residue at the C-terminus abolishes immunoreactivity. Therefore, mAb 423, together with knowledge of the N-terminus, can be used to measure the precise extent of 12 kDa PHF core tau fragment which we term the minimal protease resistant tau unit of the core PHF. This unit is 93-95 residues long, which is equivalent to three repeats, but is 14-16 residues out of phase with respect to the maximum homology organization of the repeat region. mAb 423 labels isolated PHFs prior to Pronase digestion and intracellular granular and neurofibrillary degeneration in Alzheimer's disease tissues. The constraints which determine endogenous truncation at Glu391 appear to be characteristic of an assembled configuration of tau, either within the PHF or its precursor.

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Selected References

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  1. Bondareff W., Wischik C. M., Novak M., Amos W. B., Klug A., Roth M. Molecular analysis of neurofibrillary degeneration in Alzheimer's disease. An immunohistochemical study. Am J Pathol. 1990 Sep;137(3):711–723. [PMC free article] [PubMed] [Google Scholar]
  2. Bondareff W., Wischik C. M., Novak M., Roth M. Sequestration of tau by granulovacuolar degeneration in Alzheimer's disease. Am J Pathol. 1991 Sep;139(3):641–647. [PMC free article] [PubMed] [Google Scholar]
  3. Brion J. P., Hanger D. P., Bruce M. T., Couck A. M., Flament-Durand J., Anderton B. H. Tau in Alzheimer neurofibrillary tangles. N- and C-terminal regions are differentially associated with paired helical filaments and the location of a putative abnormal phosphorylation site. Biochem J. 1991 Jan 1;273(Pt 1):127–133. doi: 10.1042/bj2730127. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Butner K. A., Kirschner M. W. Tau protein binds to microtubules through a flexible array of distributed weak sites. J Cell Biol. 1991 Nov;115(3):717–730. doi: 10.1083/jcb.115.3.717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
  6. Goedert M., Jakes R. Expression of separate isoforms of human tau protein: correlation with the tau pattern in brain and effects on tubulin polymerization. EMBO J. 1990 Dec;9(13):4225–4230. doi: 10.1002/j.1460-2075.1990.tb07870.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. 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. 1989 Oct;3(4):519–526. doi: 10.1016/0896-6273(89)90210-9. [DOI] [PubMed] [Google Scholar]
  8. Goedert M., Spillantini M. G., Potier M. C., Ulrich J., Crowther R. A. Cloning and sequencing of the cDNA encoding an isoform of microtubule-associated protein tau containing four tandem repeats: differential expression of tau protein mRNAs in human brain. EMBO J. 1989 Feb;8(2):393–399. doi: 10.1002/j.1460-2075.1989.tb03390.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Harrington C. R., Mukaetova-Ladinska E. B., Hills R., Edwards P. C., Montejo de Garcini E., Novak M., Wischik C. M. Measurement of distinct immunochemical presentations of tau protein in Alzheimer disease. Proc Natl Acad Sci U S A. 1991 Jul 1;88(13):5842–5846. doi: 10.1073/pnas.88.13.5842. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Jakes R., Novak M., Davison M., Wischik C. M. Identification of 3- and 4-repeat tau isoforms within the PHF in Alzheimer's disease. EMBO J. 1991 Oct;10(10):2725–2729. doi: 10.1002/j.1460-2075.1991.tb07820.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  12. Matsudaira P. Sequence from picomole quantities of proteins electroblotted onto polyvinylidene difluoride membranes. J Biol Chem. 1987 Jul 25;262(21):10035–10038. [PubMed] [Google Scholar]
  13. McLeod M., Stein M., Beach D. The product of the mei3+ gene, expressed under control of the mating-type locus, induces meiosis and sporulation in fission yeast. EMBO J. 1987 Mar;6(3):729–736. doi: 10.1002/j.1460-2075.1987.tb04814.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Mena R., Wischik C. M., Novak M., Milstein C., Cuello A. C. A progressive deposition of paired helical filaments (PHF) in the brain characterizes the evolution of dementia in Alzheimer's disease. An immunocytochemical study with a monoclonal antibody against the PHF core. J Neuropathol Exp Neurol. 1991 Jul;50(4):474–490. doi: 10.1097/00005072-199107000-00008. [DOI] [PubMed] [Google Scholar]
  15. Novak M., Jakes R., Edwards P. C., Milstein C., Wischik C. M. Difference between the tau protein of Alzheimer paired helical filament core and normal tau revealed by epitope analysis of monoclonal antibodies 423 and 7.51. Proc Natl Acad Sci U S A. 1991 Jul 1;88(13):5837–5841. doi: 10.1073/pnas.88.13.5837. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Novak M., Wischik C. M., Edwards P., Pannell R., Milstein C. Characterisation of the first monoclonal antibody against the pronase resistant core of the Alzheimer PHF. Prog Clin Biol Res. 1989;317:755–761. [PubMed] [Google Scholar]
  17. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Studier F. W., Rosenberg A. H., Dunn J. J., Dubendorff J. W. Use of T7 RNA polymerase to direct expression of cloned genes. Methods Enzymol. 1990;185:60–89. doi: 10.1016/0076-6879(90)85008-c. [DOI] [PubMed] [Google Scholar]
  19. 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 U S A. 1988 Jul;85(13):4884–4888. doi: 10.1073/pnas.85.13.4884. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Wischik C. M., Novak M., Thøgersen 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 U S A. 1988 Jun;85(12):4506–4510. doi: 10.1073/pnas.85.12.4506. [DOI] [PMC free article] [PubMed] [Google Scholar]

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