Screen for DNA-damage-responsive histone modifications identifies H3K9Ac and H3K56Ac in human cells

Abstract

Recognition and repair of damaged DNA occurs within the context of chromatin. The key protein components of chromatin are histones, whose post-translational modifications control diverse chromatin functions. Here, we report our findings from a large-scale screen for DNAdamage-responsive histone modifications in human cells. We have identified specific phosphorylations and acetylations on histone H3 that decrease in response to DNA damage. Significantly, we find that DNA-damage-induced changes in H3S10p, H3S28p and H3.3S31p are a consequence of cell-cycle re-positioning rather than DNA damage per se. In contrast, H3K9Ac and H3K56Ac, a mark previously uncharacterized in human cells, are rapidly and reversibly reduced in response to DNA damage. Finally, we show that the histone acetyl-transferase GCN5/KAT2A acetylates H3K56 in vitro and in vivo. Collectively, our data indicate that though most histone modifications do not change appreciably after genotoxic stress, H3K9Ac and H3K56Ac are reduced in response to DNA damage in human cells.

p53 and p16INK4A independent induction of senescence by chromatin-dependent alteration of S-phase progression

“…Key DDR-signalling components are the protein kinases Ataxia-telangiectasia-mutated (ATM) and Ataxia-telangiectasia and Rad3-related (ATR), which activate the downstream kinases CHK2 and CHK1, respectively, leading to a cell cycle arrest 17 . Furthermore, acetylation of histone H3 on lysine 56 (H3K56) has recently been shown to be mediated by p300 HAT activity and to have a critical role in packaging DNA into chromatin for DNA replication and repair [18][19][20][21][22] . We therefore investigated whether senescence induced by p300 HAT inhibition was also dependent on the activation of DDR.…”

Histone acetylation by CBP and p300 at double-strand break sites facilitates SWI/SNF chromatin remodeling and the recruitment of non-homologous end joining factors

“…This was confirmed by our system. DNA damage-induced acetylation of N-terminal lysines 9, 14, 18, 23 and 56 within histone H3 in mammalian cells was observed by immunoblot analysis (Das et al, 2009;Tjeertes et al, 2009;Yuan et al, 2009;Lee et al, 2010;Miller et al, 2010). However, the results were controversial.…”

Regulation of chromatin by histone modifications

“…Indeed, their ability to neutralize positive charges, thereby disrupting the stabilizing influence of electrostatic interactions, correlates well with this class of enzyme functioning in numerous transcriptional coactivators [6]. However, it is not just the histone tails that are involved in this regulation, but there are additional sites of acetylation present within the globular histone core, such as H3K56 that is acetylated in humans by hGCN5 [7]. The H3K56 side chain points towards the DNA major groove, suggesting that acetylation would affect histone/DNA interaction, a situation reminiscent of the proposed effects of acetylating the histone N-terminal tail lysines.…”