| Title: | VPS27 controls vacuolar and endocytic traffic through a prevacuolar compartment in Saccharomyces cerevisiae |
| Author(s): | Piper RC; Cooper AA; Yang H; Stevens TH; |
| Address: | "Institute of Molecular Biology, University of Oregon, Eugene 97403-1229, USA" |
| ISSN/ISBN: | 0021-9525 (Print) 1540-8140 (Electronic) 0021-9525 (Linking) |
| Abstract: | "Newly synthesized vacuolar hydrolases such as carboxypeptidase Y (CPY) are sorted from the secretory pathway in the late-Golgi compartment and reach the vacuole after a distinct set of membrane-trafficking steps. Endocytosed proteins are also delivered to the vacuole. It has been proposed that these pathways converge at a 'prevacuolar' step before delivery to the vacuole. One group of genes has been described that appears to control both of these pathways. Cells carrying mutations in any one of the class E VPS (vacuolar protein sorting) genes accumulate vacuolar, Golgi, and endocytosed proteins in a novel compartment adjacent to the vacuole termed the 'class E' compartment, which may represent an exaggerated version of the physiological prevacuolar compartment. We have characterized one of the class E VPS genes, VPS27, in detail to address this question. Using a temperature-sensitive allele of VPS27, we find that upon rapid inactivation of Vps27p function, the Golgi protein Vps10p (the CPY-sorting receptor) and endocytosed Ste3p rapidly accumulate in a class E compartment. Upon restoration of Vps27p function, the Vps10p that had accumulated in the class E compartment could return to the Golgi apparatus and restore correct sorting of CPY. Likewise, Ste3p that had accumulated in the class E compartment en route to the vacuole could progress to the vacuole upon restoration of Vps27p function indicating that the class E compartment can act as a functional intermediate. Because both recycling Golgi proteins and endocytosed proteins rapidly accumulate in a class E compartment upon inactivation of Vps27p, we propose that Vps27p controls membrane traffic through the prevacuolar/endosomal compartment in wild-type cells" |
| Keywords: | "Amino Acid Sequence Base Sequence Biomarkers Carboxypeptidases/metabolism Cathepsin A Cell Compartmentation/physiology Cloning, Molecular Endocytosis/*physiology Fungal Proteins/metabolism/*physiology Gene Expression/physiology Genes, Fungal/physiology Go;" |
| Notes: | "MedlinePiper, R C Cooper, A A Yang, H Stevens, T H eng GM16601-01/GM/NIGMS NIH HHS/ GM32448/GM/NIGMS NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. 1995/11/01 J Cell Biol. 1995 Nov; 131(3):603-17. doi: 10.1083/jcb.131.3.603" |
