International Cancer Center, Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Marshall Laboratory of Biomedical Engineering, Department of Biochemistry and Molecular Biology, Shenzhen University Medical School, Shenzhen, China.
Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Marshall Laboratory of Biomedical Engineering, Department of Cell Biology and Medical Genetics, Shenzhen University Medical School, Shenzhen, China.
Nat Struct Mol Biol. 2023 Nov;30(11):1719-1734. doi: 10.1038/s41594-023-01107-3. Epub 2023 Sep 21.
Chromatin relaxation is a prerequisite for the DNA repair machinery to access double-strand breaks (DSBs). Local histones around the DSBs then undergo prompt changes in acetylation status, but how the large demands of acetyl-CoA are met is unclear. Here, we report that pyruvate dehydrogenase 1α (PDHE1α) catalyzes pyruvate metabolism to rapidly provide acetyl-CoA in response to DNA damage. We show that PDHE1α is quickly recruited to chromatin in a polyADP-ribosylation-dependent manner, which drives acetyl-CoA generation to support local chromatin acetylation around DSBs. This process increases the formation of relaxed chromatin to facilitate repair-factor loading, genome stability and cancer cell resistance to DNA-damaging treatments in vitro and in vivo. Indeed, we demonstrate that blocking polyADP-ribosylation-based PDHE1α chromatin recruitment attenuates chromatin relaxation and DSB repair efficiency, resulting in genome instability and restored radiosensitivity. These findings support a mechanism in which chromatin-associated PDHE1α locally generates acetyl-CoA to remodel the chromatin environment adjacent to DSBs and promote their repair.
染色质弛豫是 DNA 修复机制接近双链断裂(DSBs)的前提。然后,DSBs 周围的局部组蛋白迅速发生乙酰化状态的改变,但乙酰辅酶 A 的大量需求是如何得到满足的尚不清楚。在这里,我们报告丙酮酸脱氢酶 1α(PDHE1α)通过催化丙酮酸代谢来快速提供乙酰辅酶 A,以响应 DNA 损伤。我们表明,PDHE1α 以多聚 ADP-核糖基化依赖的方式迅速被募集到染色质上,从而驱动乙酰辅酶 A 的产生,以支持 DSB 周围局部染色质的乙酰化。这个过程增加了松弛染色质的形成,以促进修复因子的加载、基因组稳定性和癌细胞对体外和体内 DNA 损伤处理的抗性。事实上,我们证明,阻断基于多聚 ADP-核糖基化的 PDHE1α 染色质募集会减弱染色质弛豫和 DSB 修复效率,导致基因组不稳定和恢复放射敏感性。这些发现支持了一种机制,即染色质相关的 PDHE1α 局部产生乙酰辅酶 A,以重塑 DSB 附近的染色质环境,并促进其修复。