Title: Covalent targeting of the vacuolar H+-ATPase activates autophagy via mTORC1 inhibition.

Authors: Chung, Clive Yik-Sham; Shin, Hijai R; Berdan, Charles A; Ford, Breanna; Ward, Carl C; Olzmann, James A; Zoncu, Roberto; Nomura, Daniel K

Published In Nat Chem Biol, (2019 Aug)

Abstract: Autophagy is a lysosomal degradation pathway that eliminates aggregated proteins and damaged organelles to maintain cellular homeostasis. A major route for activating autophagy involves inhibition of the mTORC1 kinase, but current mTORC1-targeting compounds do not allow complete and selective mTORC1 blockade. Here, we have coupled screening of a covalent ligand library with activity-based protein profiling to discover EN6, a small-molecule in vivo activator of autophagy that covalently targets cysteine 277 in the ATP6V1A subunit of the lysosomal v-ATPase, which activates mTORC1 via the Rag guanosine triphosphatases. EN6-mediated ATP6V1A modification decouples the v-ATPase from the Rags, leading to inhibition of mTORC1 signaling, increased lysosomal acidification and activation of autophagy. Consistently, EN6 clears TDP-43 aggregates, a causative agent in frontotemporal dementia, in a lysosome-dependent manner. Our results provide insight into how the v-ATPase regulates mTORC1, and reveal a unique approach for enhancing cellular clearance based on covalent inhibition of lysosomal mTORC1 signaling.

PubMed ID: 31285595

MeSH Terms: Animals; Autophagy/drug effects*; Autophagy/physiology; Cell Line; Gene Expression Regulation/drug effects; Gene Knockdown Techniques; Humans; Mechanistic Target of Rapamycin Complex 1/antagonists & inhibitors*; Mice; Molecular Structure; Proto-Oncogene Proteins c-akt; Pyrazoles/pharmacology; Vacuolar Proton-Translocating ATPases/metabolism*