Proapoptotic Effects of Tau Cleavage Product Generated by Caspase-3
Authors: Chung C-W.1; Song Y-H.1; Kim I-K.1; Yoon W-J.2; Ryu B-R.2; Jo D-G.1; Woo H-N.1; Kwon Y-K.1; Kim H-H.1; Gwag B-J.2; Mook-Jung I-H.2; Jung Y-K.1
Source: Neurobiology of Disease, Volume 8, Number 1, February 2001 , pp. 162-172(11)
Publisher: Academic Press
Abstract:
Using an in vitro translation assay to screen a human brain cDNA library, we isolated the microtubule-associated protein Tau and determined it to be a caspase-3 substrate whose C-terminal cleavage occurred during neuronal apoptosis.
Tau, the 50-kDa cleavage product, was detected by Western blot in apoptotic cortical cells probed with anti-PHF-1 and anti-Tau-5 antibodies, but not anti-T-46 antibody which recognizes the C-terminus. Overexpression of
Tau in SK-N-BE2(C) cells significantly increased the incidence of cell death. Staurosporine-induced Tau cleavage was blocked by 20
M z-Asp-Glu-Val-Asp-chloromethylketone, a caspase-3 inhibitor, and in vitro, Tau was selectively cleaved by caspase-3 or calpain, a calcium-activated protease, but not by caspases-1, -8, or -9. (D421E)-Tau, a mutant in which Asp421 was replaced with a Glu, was resistant to cleavage by caspase-3 and tended to suppress staurosporine-induced cell death more efficiently than did wild-type Tau in both transient and stable expression systems. Finally, the incidence of
Tau-induced cell death was augmented by expression of A
precursor protein (APP) or Swedish APP mutant. Taken together, these results suggest that the caspase-3 cleavage product of Tau may contribute to the progression of neuronal cell death in Alzheimer's disease. Copyright 2001 Academic Press.
Language: English
Document Type: Research article
Affiliations: 1: Biomedical Brain Research Center, National Institute of Health, Puk-Gu, Kwangju, 500-712, Korea 2: Department of Pharmacology, Ajou University School of Medicine, Suwon, Kyungkido, Korea

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