%0 Journal Article
%T Role of Polycomb Group Proteins in the DNA Damage Response ¨C A Reassessment
%A Hollie Chandler
%A Harshil Patel
%A Richard Palermo
%A Sharon Brookes
%A Nik Matthews
%A Gordon Peters
%J PLOS ONE
%D 2014
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0102968
%X A growing body of evidence suggests that Polycomb group (PcG) proteins, key regulators of lineage specific gene expression, also participate in the repair of DNA double-strand breaks (DSBs) but evidence for direct recruitment of PcG proteins at specific breaks remains limited. Here we explore the association of Polycomb repressive complex 1 (PRC1) components with DSBs generated by inducible expression of the AsiSI restriction enzyme in normal human fibroblasts. Based on immunofluorescent staining, the co-localization of PRC1 proteins with components of the DNA damage response (DDR) in these primary cells is unconvincing. Moreover, using chromatin immunoprecipitation and deep sequencing (ChIP-seq), which detects PRC1 proteins at common sites throughout the genome, we did not find evidence for recruitment of PRC1 components to AsiSI-induced DSBs. In contrast, the S2056 phosphorylated form of DNA-PKcs and other DDR proteins were detected at a subset of AsiSI sites that are predominantly at the 5¡ä ends of transcriptionally active genes. Our data question the idea that PcG protein recruitment provides a link between DSB repairs and transcriptional repression.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0102968