The TORC1 activates Rpd3L complex to deacetylate Ino80 and H2A.Z and repress autophagy

Abstract

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.