{"title":"mTORC1 activity licenses its own release from the lysosomal surface","authors":"Aishwarya Acharya, Constantinos Demetriades","doi":"10.1016/j.molcel.2024.10.008","DOIUrl":null,"url":null,"abstract":"Nutrient signaling converges on mTORC1, which, in turn, orchestrates a physiological cellular response. A key determinant of mTORC1 activity is its shuttling between the lysosomal surface and the cytoplasm, with nutrients promoting its recruitment to lysosomes by the Rag GTPases. Active mTORC1 regulates various cellular functions by phosphorylating distinct substrates at different subcellular locations. Importantly, how mTORC1 that is activated on lysosomes is released to meet its non-lysosomal targets and whether mTORC1 activity itself impacts its localization remain unclear. Here, we show that, in human cells, mTORC1 inhibition prevents its release from lysosomes, even under starvation conditions, which is accompanied by elevated and sustained phosphorylation of its lysosomal substrate TFEB. Mechanistically, “inactive” mTORC1 causes persistent Rag activation, underlining its release as another process actively mediated via the Rags. In sum, we describe a mechanism by which mTORC1 controls its own localization, likely to prevent futile cycling on and off lysosomes.","PeriodicalId":18950,"journal":{"name":"Molecular Cell","volume":"3 1","pages":""},"PeriodicalIF":14.5000,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Cell","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.molcel.2024.10.008","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Nutrient signaling converges on mTORC1, which, in turn, orchestrates a physiological cellular response. A key determinant of mTORC1 activity is its shuttling between the lysosomal surface and the cytoplasm, with nutrients promoting its recruitment to lysosomes by the Rag GTPases. Active mTORC1 regulates various cellular functions by phosphorylating distinct substrates at different subcellular locations. Importantly, how mTORC1 that is activated on lysosomes is released to meet its non-lysosomal targets and whether mTORC1 activity itself impacts its localization remain unclear. Here, we show that, in human cells, mTORC1 inhibition prevents its release from lysosomes, even under starvation conditions, which is accompanied by elevated and sustained phosphorylation of its lysosomal substrate TFEB. Mechanistically, “inactive” mTORC1 causes persistent Rag activation, underlining its release as another process actively mediated via the Rags. In sum, we describe a mechanism by which mTORC1 controls its own localization, likely to prevent futile cycling on and off lysosomes.
期刊介绍:
Molecular Cell is a companion to Cell, the leading journal of biology and the highest-impact journal in the world. Launched in December 1997 and published monthly. Molecular Cell is dedicated to publishing cutting-edge research in molecular biology, focusing on fundamental cellular processes. The journal encompasses a wide range of topics, including DNA replication, recombination, and repair; Chromatin biology and genome organization; Transcription; RNA processing and decay; Non-coding RNA function; Translation; Protein folding, modification, and quality control; Signal transduction pathways; Cell cycle and checkpoints; Cell death; Autophagy; Metabolism.