Spatial organization of the mammalian genome surveillance machinery in response to DNA strand breaks.

Journal Article (Journal Article)

We show that DNA double-strand breaks (DSBs) induce complex subcompartmentalization of genome surveillance regulators. Chromatin marked by gamma-H2AX is occupied by ataxia telangiectasia-mutated (ATM) kinase, Mdc1, and 53BP1. In contrast, repair factors (Rad51, Rad52, BRCA2, and FANCD2), ATM and Rad-3-related (ATR) cascade (ATR, ATR interacting protein, and replication protein A), and the DNA clamp (Rad17 and -9) accumulate in subchromatin microcompartments delineated by single-stranded DNA (ssDNA). BRCA1 and the Mre11-Rad50-Nbs1 complex interact with both of these compartments. Importantly, some core DSB regulators do not form cytologically discernible foci. These are further subclassified to proteins that connect DSBs with the rest of the nucleus (Chk1 and -2), that assemble at unprocessed DSBs (DNA-PK/Ku70), and that exist on chromatin as preassembled complexes but become locally modified after DNA damage (Smc1/Smc3). Finally, checkpoint effectors such as p53 and Cdc25A do not accumulate at DSBs at all. We propose that subclassification of DSB regulators according to their residence sites provides a useful framework for understanding their involvement in diverse processes of genome surveillance.

Full Text

Duke Authors

Cited Authors

  • Bekker-Jensen, S; Lukas, C; Kitagawa, R; Melander, F; Kastan, MB; Bartek, J; Lukas, J

Published Date

  • April 24, 2006

Published In

Volume / Issue

  • 173 / 2

Start / End Page

  • 195 - 206

PubMed ID

  • 16618811

Pubmed Central ID

  • PMC2063811

International Standard Serial Number (ISSN)

  • 0021-9525

Digital Object Identifier (DOI)

  • 10.1083/jcb.200510130


  • eng

Conference Location

  • United States