Table 3.

HDAC2 regulation in histone acetylation and methylation in DDR and cellular senescence

Histone Modification	Specific Residue	Effect of HDAC2	Function	Reference
Acetylation	H3K56	Reduce its acetylation	Involved in DDR and DNA repair	(82)
	H4K5	Reduce its acetylation	Involved in DNA repair	(41, 105)
	H4K12	Reduce its acetylation	Regulate telomere function and premature aging	(41, 50, 105, 145)
	H4K16	Reduce its acetylation	Involved in DNA repair and cellular senescence	(59, 82)
Methylation	H3K4	HDACs inhibit H3K4 methylation via LSD1	Involved in gene activation and DDR	(30, 45, 77, 132)
	H3K9	HDACs increase its methylation via SUV39H1	Involved in replication checkpoint and cellular senescence	(13, 87, 102, 127)
	H4K20	Trichostatin A reduces its methylation	Influence DDR after DSB	(12, 36, 106)

DDR, DNA damage response; DSB, double-strand break.