Reaction: WHSC1 dimethylates histone H4 on lysine K21 at DSBs
- in pathway: Recruitment and ATM-mediated phosphorylation of repair and signaling proteins at DNA double strand breaks
WHSC1 (MMSET) histone methyltransferase dimethylates histone H4 (HIST1H4A) on lysine residue K21 (commonly labeled in literature as K20), locally increasing the concentration of the H4K20Me2 mark. H4K20Me2 (Me2-K21-HIST1H4A) serves as a binding site for TP53BP1 (53BP1). The recruitment of WHSC1 to DNA double-strand breaks (DSBs) is independent of RNF8 and RNF168, but the catalytic activity of all three proteins is necessary for binding and accumulation of TP53BP1 at DSBs (Pei et al. 2011).
Reaction - small molecule participants:
AdoHcy [nucleoplasm]
AdoMet [nucleoplasm]
Reactome.org reaction link: R-HSA-5682965
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Reaction input - small molecules:
S-adenosyl-L-methionine zwitterion
Reaction output - small molecules:
S-adenosyl-L-homocysteine zwitterion
Reactome.org link: R-HSA-5682965