Biogenesis of autophagosomal precursors for LC3 lipidation from the ER-Golgi intermediate compartment

Abstract

Autophagosome biogenesis requires efficient mobilization and delivery of membranes from intracellular sources. How these membranes are mobilized remains poorly understood. Our recent work reported an autophagic signalinduced membrane mobilization event from the ER-Golgi intermediate compartment (ERGIC) to generate an early autophagosomal membrane precursor. We found that starvation activates the autophagic phosphatidylinositol 3- kinase, which promotes a relocation of COPII proteins from the ER-exit sites to the ERGIC. The relocation of COPII generates ERGIC-derived COPII vesicles as a membrane template for LC3 lipidation, a key step for autophagosome biogenesis.