Table_1_Chk1 Inhibition Hinders the Restoration of H3.1K56 and H3.3K56 Acetylation and Reprograms Gene Transcription After DNA Damage Repair.xlsx

H3K56 acetylation (H3K56Ac) was reported to play a critical role in chromatin assembly; thus, H3K56ac participates in the regulation of DNA replication, cell cycle progression, DNA repair, and transcriptional activation. To investigate the influence of DNA damage regulators on the acetylation of histone H3 and gene transcription, U2OS cells expressing SNAP-labeled H3.1 or SNAP-labeled H3.3 were treated with ATM, ATR, or a Chk1 inhibitor after ultraviolet (UV) radiation. The levels of H3.1K56ac, H3.3K56ac, and other H3 site-specific acetylation were checked at different time points until 24 h after UV radiation. The difference in gene transcription levels was also examined by mRNA sequencing. The results identified Chk1 as an important regulator of histone H3K56 acetylation in the restoration of both H3.1K56ac and H3.3K56ac. Moreover, compromising Chk1 activity via chemical inhibitors suppresses gene transcription after UV radiation. The study suggests a previously unknown role of Chk1 in regulating H3K56 and some other site-specific H3 acetylation and in reprograming gene transcription during DNA damage repair.

H3K56乙酰化（H3K56 acetylation, H3K56Ac）据报道在染色质组装过程中发挥关键作用，因此其参与调控DNA复制、细胞周期进程、DNA修复及转录激活。为探究DNA损伤调控因子对组蛋白H3乙酰化及基因转录的影响，本研究将表达SNAP标记H3.1或SNAP标记H3.3的U2OS细胞经紫外线（UV）辐射处理后，分别采用ATM、ATR抑制剂或Chk1抑制剂进行干预。于紫外线辐射后不同时间点（直至24小时）检测H3.1K56ac、H3.3K56ac及其他H3位点特异性乙酰化水平，并通过mRNA测序分析基因转录水平的差异。研究结果显示，Chk1是调控紫外线辐射后H3.1K56ac与H3.3K56ac恢复过程中组蛋白H3K56乙酰化的关键调控因子。此外，通过化学抑制剂抑制Chk1活性，可削弱紫外线辐射后的基因转录水平。本研究揭示了Chk1在DNA损伤修复过程中调控H3K56及其他部分H3位点特异性乙酰化、并重编程基因转录的全新功能。