Stress-induced microautophagy is coordinated with lysosome biogenesis and regulated by PIKfyve Journal Article


Authors: Klein, A. D.; Petruzzi, K. L.; Lee, C.; Overholtzer, M.
Article Title: Stress-induced microautophagy is coordinated with lysosome biogenesis and regulated by PIKfyve
Abstract: Lysosome turnover and biogenesis are induced in response to treatment of cells with agents that cause membrane rupture, but whether other stress conditions engage similar homeostatic mechanisms is not well understood. Recently we described a form of selective turnover of lysosomes that is induced by metabolic stress or by treatment of cells with ionophores or lysosomotropic agents, involving the formation of intraluminal vesicles within intact organelles through microautophagy. Selective turnover involves noncanonical autophagy and the lipidation of LC3 onto lysosomal membranes, as well as the autophagy gene-dependent formation of intraluminal vesicles. Here, we find a form of microautophagy induction that requires activity of the lipid kinase PIKfyve and is associated with the nuclear translocation of TFEB, a known mediator of lysosome biogenesis. We show that LC3 undergoes turnover during this process, and that PIKfyve is required for the formation of intraluminal vesicles and LC3 turnover, but not for LC3 lipidation onto lysosomal membranes, demonstrating that microautophagy is regulated by PIKfyve downstream of noncanonical autophagy. We further show that TFEB activation requires noncanonical autophagy but not PIKfyve, distinguishing the regulation of biogenesis from microautophagy occurring in response to agents that induce lysosomal stress.
Keywords: metabolism; autophagy; lysosome; lysosomes; basic helix loop helix leucine zipper transcription factor; basic helix-loop-helix leucine zipper transcription factors; intracellular membranes; ionophore; ionophores; intracellular membrane; microautophagy
Journal Title: Molecular Biology of the Cell
Volume: 35
Issue: 5
ISSN: 1059-1524
Publisher: The American Society for Cell Biology  
Date Published: 2024-05-01
Start Page: ar70
Language: English
DOI: 10.1091/mbc.E23-08-0332
PUBMED: 38536415
PROVIDER: scopus
PMCID: PMC11151102
DOI/URL:
Notes: Article -- MSK corresponding author is Michael Overholtzer -- Source: Scopus
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MSK Authors
  1. Chan Lee
    4 Lee
  2. Alison Drake Klein
    2 Klein