Chemical proteomics reveals a ?H2AX-53BP1 interaction in the DNA damage response.

ABSTRACT: DNA double-strand break repair involves phosphorylation of histone variant H2AX ('?H2AX'), which accumulates in foci at sites of DNA damage. In current models, the recruitment of multiple DNA repair proteins to ?H2AX foci depends mainly on recognition of this 'mark' by a single protein, MDC1. However, DNA repair proteins accumulate at ?H2AX sites without MDC1, suggesting that other 'readers' of this mark exist. Here, we use a quantitative chemical proteomics approach to profile direct, phospho-selective ?H2AX binders in native proteomes. We identify ?H2AX binders, including the DNA repair mediator 53BP1, which we show recognizes ?H2AX through its BRCT domains. Furthermore, we investigate the targeting of wild-type 53BP1, or a mutant form deficient in ?H2AX binding, to chromosomal breaks resulting from endogenous and exogenous DNA damage. Our results show how direct recognition of ?H2AX modulates protein localization at DNA damage sites, and suggest how specific chromatin mark-reader interactions contribute to essential mechanisms ensuring genome stability.

SUBMITTER: Kleiner RE 

PROVIDER: S-EPMC4589150 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature