Phospholipid imbalance impairs autophagosome completion

Alexandra Polyansky, Oren Shatz, Milana Fraiberg, Eyal Shimoni, Tali Dadosh, Muriel Mari, Fulvio M. Reggiori, Chao Qin, Xianlin Han, Zvulun Elazar

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Autophagy, a conserved eukaryotic intracellular catabolic pathway, maintains cell homeostasis by lysosomal degradation of cytosolic material engulfed in double membrane vesicles termed autophagosomes, which form upon sealing of single-membrane cisternae called phagophores. While the role of phosphatidylinositol 3-phosphate (PI3P) and phosphatidylethanolamine (PE) in autophagosome biogenesis is well-studied, the roles of other phospholipids in autophagy remain rather obscure. Here we utilized budding yeast to study the contribution of phosphatidylcholine (PC) to autophagy. We reveal for the first time that genetic loss of PC biosynthesis via the CDP-DAG pathway leads to changes in lipid composition of autophagic membranes, specifically replacement of PC by phosphatidylserine (PS). This impairs closure of the autophagic membrane and autophagic flux. Consequently, we show that choline-dependent recovery of de novo PC biosynthesis via the CDP-choline pathway restores autophagosome formation and autophagic flux in PC-deficient cells. Our findings therefore implicate phospholipid metabolism in autophagosome biogenesis.

Original languageEnglish (US)
Article numbere110771
JournalEMBO Journal
Volume41
Issue number23
DOIs
StatePublished - Dec 1 2022

Keywords

  • autophagosome biogenesis
  • autophagy
  • phagophore
  • phospholipids

ASJC Scopus subject areas

  • General Immunology and Microbiology
  • General Biochemistry, Genetics and Molecular Biology
  • Molecular Biology
  • General Neuroscience

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