Phosphatidylinositol 4,5-bisphosphate controls Rab7 and PLEKHM1 membrane cycling during autophagosome-lysosome fusion.

ABSTRACT: The small GTPase Rab7 is a key organizer of receptor sorting and lysosomal degradation by recruiting of a variety of effectors depending on its GDP/GTP-bound state. However, molecular mechanisms that trigger Rab7 inactivation remain elusive. Here we find that, among the endosomal pools, Rab7-positive compartments possess the highest level of PI4P, which is primarily produced by PI4K2A kinase. Acute conversion of this endosomal PI4P to PI(4,5)P₂ causes Rab7 dissociation from late endosomes and releases a regulator of autophagosome-lysosome fusion, PLEKHM1, from the membrane. Rab7 effectors Vps35 and RILP are not affected by acute PI(4,5)P₂ production. Deletion of PI4K2A greatly reduces PIP5Kγ-mediated PI(4,5)P₂ production in Rab7-positive endosomes leading t

SUBMITTER: Baba T 

PROVIDER: S-EPMC6463214 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature