The dynamin-related protein Vps1 and the peroxisomal membrane protein Pex27 function together during peroxisome fission

Dynamin-related proteins (Drps) mediate a variety of membrane remodelling processes. The Saccharomyces cerevisiae Drp, Vps1, is required for endocytosis, endosomal sorting, vacuole fusion, and peroxisome fission and breakdown. How Drps, and in particular Vps1, can function at so many different subcellular locations is of interest to our understanding of cellular organisation. We found that the peroxisomal membrane protein Pex27 is specifically required for Vps1-dependent peroxisome fission in proliferating cells but is not required for Dnm1-dependent peroxisome fission. Pex27 accumulates in constricted regions of peroxisomes and affects peroxisome geometry upon overexpression. Moreover, Pex27 physically interacts with Vps1 in vivo and is required for the accumulation of a GTPase-defective Vps1 mutant (K42A) on peroxisomes. During nitrogen starvation, a condition that halts cell division and induces peroxisome breakdown, Vps1 associates with the pexophagophore. Pex27 is neither required for Vps1 recruitment to the pexophagophore nor for pexophagy. Our study identifies Pex27 as a Vps1-specific partner for the maintenance of peroxisome number in proliferating yeast cells.

Automated summary

Dynamin-related proteins (Drps) play a role in various membrane remodelling processes. The yeast Drp, Vps1, is involved in endocytosis, endosomal sorting, vacuole fusion, and peroxisome fission and breakdown. Our study highlights the specific requirement of peroxisomal membrane protein Pex27 for Vps1-dependent peroxisome fission in proliferating yeast cells. Pex27 interacts with Vps1 and affects peroxisome geometry. Pex27 is not involved in the association of Vps1 with pexophagophores during nitrogen starvation.