ESCRT-III-driven piecemeal micro-ER-phagy remodels the ER during recovery from ER stress

Marisa Loi, Andrea Raimondi, Diego Morone, Maurizio Molinari

Research output: Contribution to journalArticle

Abstract

The endoplasmic reticulum (ER) produces about 40% of the nucleated cell’s proteome. ER size and content in molecular chaperones increase upon physiologic and pathologic stresses on activation of unfolded protein responses (UPR). On stress resolution, the mammalian ER is remodeled to pre-stress, physiologic size and function on activation of the LC3-binding activity of the translocon component SEC62. This elicits recov-ER-phagy, i.e., the delivery of the excess ER generated during the phase of stress to endolysosomes (EL) for clearance. Here, ultrastructural and genetic analyses reveal that recov-ER-phagy entails the LC3 lipidation machinery and proceeds via piecemeal micro-ER-phagy, where RAB7/LAMP1-positive EL directly engulf excess ER in processes that rely on the Endosomal Sorting Complex Required for Transport (ESCRT)-III component CHMP4B and the accessory AAA+ ATPase VPS4A. Thus, ESCRT-III-driven micro-ER-phagy emerges as a key catabolic pathway activated to remodel the mammalian ER on recovery from ER stress.

Original languageEnglish
Article number5058
JournalNature Communications
Volume10
Issue number1
DOIs
Publication statusPublished - Dec 1 2019

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'ESCRT-III-driven piecemeal micro-ER-phagy remodels the ER during recovery from ER stress'. Together they form a unique fingerprint.

  • Cite this