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ATP activates ataxia-telangiectasia mutated (ATM) in vitro. Importance of autophosphorylation

Citation

Kozlov, S and Gueven, N and Keating, K and Ramsay, J and Lavin, MF, ATP activates ataxia-telangiectasia mutated (ATM) in vitro. Importance of autophosphorylation, Journal of Biological Chemistry, 278, (11) pp. 9309-9317. ISSN 0021-9258 (2003) [Refereed Article]

Copyright Statement

Copyright 2003 by The American Society for Biochemistry and Molecular Biology, Inc

DOI: doi:10.1074/jbc.M300003200

Abstract

Ataxia-telangiectasia Mutated (ATM), mutated in the human disorder ataxia-telangiectasia, is rapidly activated by DNA double strand breaks. The mechanism of activation remains unresolved, and it is uncertain whether autophosphorylation contributes to activation. We describe an in vitro immunoprecipitation system demonstrating activation of ATM kinase from unirradiated extracts by preincubation with ATP. Activation is both time- and ATP concentration-dependent, other nucleotides fail to activate ATM, and DNA is not required. ATP activation is specific for ATM since it is not observed with kinase-dead ATM, it requires Mn2+, and it is inhibited by wortmannin. Exposure of activated ATM to phosphatase abrogates activity, and repeat cycles of ATP and phosphatase treatment reveal a requirement for autophosphorylation in the activation process. Phosphopeptide mapping revealed similarities between the patterns of autophosphorylation for irradiated and ATP-treated ATM. Caffeine inhibited ATM kinase activity for substrates but did not interfere with ATM autophosphorylation. ATP failed to activate either A-T and rad3-related protein (ATR) or DNA-dependent protein kinase under these conditions, supporting the specificity for ATM. These data demonstrate that ATP can specifically induce activation of ATM by a mechanism involving autophosphorylation. The relationship of this activation to DNA damage activation remains unclear but represents a useful model for understanding in vivo activation.

Item Details

Item Type:Refereed Article
Keywords:activation of the ATM promoter
Research Division:Biological Sciences
Research Group:Biochemistry and Cell Biology
Research Field:Signal Transduction
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Biological Sciences
Author:Gueven, N (Dr Nuri Guven)
ID Code:79323
Year Published:2003
Web of Science® Times Cited:61
Deposited By:Pharmacy
Deposited On:2012-08-31
Last Modified:2014-11-05
Downloads:0

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