State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China.
Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China.
Sci Adv. 2023 Mar 10;9(10):eade8312. doi: 10.1126/sciadv.ade8312. Epub 2023 Mar 8.
Autophagy is a critical process to maintain homeostasis, differentiation, and development. How autophagy is tightly regulated by nutritional changes is poorly understood. Here, we identify chromatin remodeling protein Ino80 and histone variant H2A.Z as the deacetylation targets for histone deacetylase Rpd3L complex and uncover how they regulate autophagy in response to nutrient availability. Mechanistically, Rpd3L deacetylates Ino80 K929, which protects Ino80 from being degraded by autophagy. The stabilized Ino80 promotes H2A.Z eviction from autophagy-related genes, leading to their transcriptional repression. Meanwhile, Rpd3L deacetylates H2A.Z, which further blocks its deposition into chromatin to repress the transcription of autophagy-related genes. Rpd3-mediated deacetylation of Ino80 K929 and H2A.Z is enhanced by the target of rapamycin complex 1 (TORC1). Inactivation of TORC1 by nitrogen starvation or rapamycin inhibits Rpd3L, leading to induction of autophagy. Our work provides a mechanism for chromatin remodelers and histone variants in modulating autophagy in response to nutrient availability.
自噬是维持体内平衡、分化和发育的关键过程。自噬如何受到营养变化的严格调节还知之甚少。在这里,我们确定染色质重塑蛋白 Ino80 和组蛋白变体 H2A.Z 是组蛋白去乙酰化酶 Rpd3L 复合物的去乙酰化靶标,并揭示了它们如何响应营养可用性来调节自噬。在机制上,Rpd3L 去乙酰化 Ino80 K929,这可防止自噬降解 Ino80。稳定的 Ino80 促进 H2A.Z 从自噬相关基因中逐出,导致其转录抑制。同时,Rpd3L 去乙酰化 H2A.Z,这进一步阻止其沉积到染色质中,从而抑制自噬相关基因的转录。雷帕霉素靶蛋白复合物 1 (TORC1) 增强了 Rpd3 介导的 Ino80 K929 和 H2A.Z 的去乙酰化。氮饥饿或雷帕霉素对 TORC1 的失活抑制 Rpd3L,导致自噬的诱导。我们的工作为染色质重塑因子和组蛋白变体在响应营养可用性调节自噬提供了一种机制。