Pkh1/2 dependent phosphorylation of Vps27 regulates ESCRT-I recruitment to endosomes.

Multivesicular endosomes (MVB) are major sorting platforms for membrane proteins and participate to plasma membrane protein turnover, vacuolar/lysosomal hydrolases delivery and surface receptor signal attenuation. MVB undergo unconventional inward budding, which results in the formation of intraluminal vesicles (ILV). MVB cargo sorting and ILV formation are achieved by the concerted ...
function of the endosomal sorting complex required for transport (ESCRT)-0 to -III. The ESCRT-0 subunit Vps27 is a key player in this pathway since it recruits the other complexes to endosomes. Here we show that the Pkh1/Phk2 kinases, two yeast orthologues of the 3-phosphoinositide-dependent kinase (PDK1) phosphorylate directly Vps27 in vivo and in vitro. We identified the phosphorylation site as the serine 613 and demonstrated that this phosphorylation is required for the proper Vps27 function. Indeed in the pkh-ts temperature-sensitive mutant cells and in cells expressing vps27(S613A), the MVB sorting of the carboxypeptidase Cps1 and of the alpha-factor receptor Ste2 is affected and the Vps28-GFP ESCRT-I subunit is mainly cytoplasmic. We propose that Vps27 phosphorylation by Pkh1/2 kinases regulates the coordinated cascade of ESCRT complexes recruitment at the endosomal membrane.
Mol. Biol. Cell
Date: Aug. 23, 2012
Download Curated Data For This Publication
145128
Switch View:
  • Interactions 3