The plasma membrane as a control center for autophagy

Autophagy. 2012 May 1;8(5):861-3. doi: 10.4161/auto.20060. Epub 2012 May 1.

Abstract

Autophagosomes may derive membrane from diverse sources, including the plasma membrane, Golgi, endoplasmic reticulum and mitochondria. The plasma membrane contributes membrane to ATG12-ATG5-ATG16L1-positive phagophore precursor vesicles (LC3-negative) by both clathrin-dependent and -independent routes. We recently observed that ARF6 regulates autophagy and that this could be explained, at least in part, by its role in the generation of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P 2], which influences endocytic uptake of plasma membrane into autophagosome precursors. The subsequent maturation of these small phagophore precursors into phagophores (ATG12-ATG5-ATG16L1-positive and LC3-positive), is assisted by SNARE-mediated homotypic fusion that increase their size and enhance their ability to acquire LC3-II. It appears that a plasma membrane-derived pool of VAMP7 is a key mediator of these fusion events. Thus, events at the plasma membrane may regulate distinct steps in the biogenesis of phagophores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autophagy*
  • Cell Membrane / metabolism*
  • Endocytosis
  • Humans
  • Lysosomes / metabolism
  • Models, Biological
  • R-SNARE Proteins / metabolism

Substances

  • R-SNARE Proteins