Microautophagy of Cytosolic Proteins by Late Endosomes

Ranjit Sahu, Susmita Kaushik, Cristina C. Clement, Elvira S. Cannizzo, Brian Scharf, Antonia Follenzi, Ilaria Potolicchio, Edward Nieves, Ana Maria Cuervo, Laura Santambrogio

Research output: Contribution to journalArticle

390 Scopus citations

Abstract

Autophagy delivers cytosolic components to lysosomes for their degradation. The delivery of autophagic cargo to late endosomes for complete or partial degradation has also been described. In this report we present evidence that distinct autophagic mechanisms control cytosolic protein delivery to late endosomes and identify a microautophagy-like process that delivers soluble cytosolic proteins to the vesicles of late endosomes/multivesicular bodies (MVBs). This microautophagy-like process has selectivity and is distinct from chaperone-mediated autophagy that occurs in lysosomes. Endosomal microautophagy occurs during MVB formation, relying on the ESCRT I and III systems for formation of the vesicles in which the cytosolic cargo is internalized. Protein cargo selection is mediated by the chaperone hsc70 and requires the cationic domain of hsc70 for electrostatic interactions with the endosomal membrane. Therefore, we propose that endosomal microautophagy shares molecular components with both the endocytic and autophagic pathways.

Original languageEnglish (US)
Pages (from-to)131-139
Number of pages9
JournalDevelopmental Cell
Volume20
Issue number1
DOIs
StatePublished - Jan 18 2011

ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Developmental Biology
  • Cell Biology

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    Sahu, R., Kaushik, S., Clement, C. C., Cannizzo, E. S., Scharf, B., Follenzi, A., Potolicchio, I., Nieves, E., Cuervo, A. M., & Santambrogio, L. (2011). Microautophagy of Cytosolic Proteins by Late Endosomes. Developmental Cell, 20(1), 131-139. https://doi.org/10.1016/j.devcel.2010.12.003