Membrane scission driven by the PROPPIN Atg18.

ABSTRACT: Sorting, transport, and autophagic degradation of proteins in endosomes and lysosomes, as well as the division of these organelles, depend on scission of membrane-bound tubulo-vesicular carriers. How scission occurs is poorly understood, but family proteins bind these membranes. Here, we show that the yeast PROPPIN Atg18 carries membrane scission activity. Purified Atg18 drives tubulation and scission of giant unilamellar vesicles. Upon membrane contact, Atg18 folds its unstructured CD loop into an amphipathic α-helix that inserts into the bilayer. This allows the protein to engage its two lipid binding sites for PI3P and PI(3,5)P₂ PI(3,5)P₂ induces Atg18 oligomerization, which should concentrate lipid-inserted α-helices in the outer membrane leaflet and drive membran

SUBMITTER: Gopaldass N 

PROVIDER: S-EPMC5686546 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature