Mutations in the VPS45 gene, a SEC1 homologue, result in vacuolar protein sorting defects and accumulation of membrane vesicles

1994 ◽  
Vol 107 (12) ◽  
pp. 3449-3459 ◽  
Author(s):  
C.R. Cowles ◽  
S.D. Emr ◽  
B.F. Horazdovsky
Keyword(s):  
High Speed ◽  
Plasma Membranes ◽  
Protein Transport ◽  
Protein Sorting ◽  
Polyclonal Antiserum ◽  
Small Subset ◽  
Vacuolar Protein Sorting ◽  
Cell Extracts ◽  
Transport Vesicles ◽  
Vacuolar Protein

Genetic analyses of vacuolar protein sorting in Saccharomyces cerevisiae have uncovered a large number of mutants (vps) that missort and secrete vacuolar hydrolases. A small subset of vps mutants exhibit a temperature-conditional growth phenotype and show a severe defect in the localization of soluble vacuolar proteins, yet maintain a near-normal vacuole structure. Here, we report on the cloning and characterization of the gene affected in one of these mutants, VPS45, which has been found to encode a member of a protein family that includes the yeast proteins Sec1p, Sly1p and Vps33p, as well as n-Sec1, UNC18 and Rop from other eukaryotic organisms. These proteins are thought to participate in vesicle-mediated protein transport events. Polyclonal antiserum raised against a TrpE-Vps45 fusion protein specifically detects a stable 67 kDa protein in labeled yeast cell extracts. Subcellular fractionation studies demonstrate that the majority of Vps45p is associated with a high-speed membrane pellet fraction that includes Golgi, transport vesicles and, potentially, endosomal membranes. Significantly, this fraction lacks ER, vacuole and plasma membranes. Overexpression of Vps45p saturates the sites with which Vps45p associates. A vps45 null mutant accumulates vesicles, many of which were found to be present in large clusters. This accumulation of potential transport vesicles indicates that Vps45p may facilitate the targeting and/or fusion of these vesicles in the vacuolar protein sorting pathway.

scholarly journals A Novel RING Finger Protein Complex Essential for a Late Step in Protein Transport to the Yeast Vacuole

1997 ◽  
Vol 8 (11) ◽  
pp. 2307-2327 ◽  
Author(s):  
Stephanie E. Rieder ◽  
Scott D. Emr
Keyword(s):  
Protein Complex ◽  
Protein Transport ◽  
Protein Sorting ◽  
Ring Finger ◽  
Endocytic Pathway ◽  
Vacuolar Protein Sorting ◽  
Oligomeric Protein ◽  
Late Step ◽  
Class C ◽  
Vacuolar Protein

Protein transport to the lysosome-like vacuole in yeast is mediated by multiple pathways, including the biosynthetic routes for vacuolar hydrolases, the endocytic pathway, and autophagy. Among the more than 40 genes required for vacuolar protein sorting (VPS) inSaccharomyces cerevisiae, mutations in the four class CVPS genes result in the most severe vacuolar protein sorting and morphology defects. Herein, we provide complementary genetic and biochemical evidence that the class C VPSgene products (Vps18p, Vps11p, Vps16p, and Vps33p) physically and functionally interact to mediate a late step in protein transport to the vacuole. Chemical cross-linking experiments demonstrated that Vps11p and Vps18p, which both contain RING finger zinc-binding domains, are components of a hetero-oligomeric protein complex that includes Vps16p and the Sec1p homologue Vps33p. The class C Vps protein complex colocalized with vacuolar membranes and a distinct dense membrane fraction. Analysis of cells harboring a temperature-conditionalvps18 allele (vps18tsf) indicated that Vps18p function is required for the biosynthetic, endocytic, and autophagic protein transport pathways to the vacuole. In addition,vps18tsfcells accumulated multivesicular bodies, autophagosomes, and other membrane compartments that appear to represent blocked transport intermediates. Overproduction of either Vps16p or the vacuolar syntaxin homologue Vam3p suppressed defects associated with vps18tsfmutant cells, indicating that the class C Vps proteins and Vam3p may functionally interact. Thus we propose that the class C Vps proteins are components of a hetero-oligomeric protein complex that mediates the delivery of multiple transport intermediates to the vacuole.

scholarly journals An Interorganellar Bidding War: Vps13 Localization by Competitive Organelle-Specific Adaptors

Contact ◽  
2018 ◽  
Vol 1 ◽  
pp. 251525641881462
Author(s):  
Samantha K. Dziurdzik ◽  
Björn D.M. Bean ◽  
Elizabeth Conibear
Keyword(s):  
Endoplasmic Reticulum ◽  
Recent Work ◽  
Protein Sorting ◽  
Repeat Region ◽  
Vacuolar Protein Sorting ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Prospore Membrane ◽  
Membrane Contact ◽  
Vacuolar Protein

Membrane contact sites are regulated through the controlled recruitment of constituent proteins. Yeast vacuolar protein sorting 13 (Vps13) dynamically localizes to membrane contact sites at endosomes, vacuoles, mitochondria, and the endoplasmic reticulum under different cellular conditions and is recruited to the prospore membrane during meiosis. Prior to our recent work, the mechanism for localization at contact sites was largely unknown. We identified Ypt35 as a novel Vps13 adaptor for endosomes and the nucleus-vacuole junction. Furthermore, we discovered a conserved recruitment motif in Ypt35 and found related motifs in the prospore membrane and mitochondrial adaptors, Spo71 and Mcp1, respectively. All three adaptors compete for binding to a six-repeat region of Vps13, suggesting adaptor competition regulates Vps13 localization. Here, we summarize and discuss the implications of our work, highlighting key outstanding questions.

Nystatin Sensitive and Vacuolar Protein Sorting Defective (vps) Mutants of Saccharomyces cerevisiae: Their Isolation and Characterization

2001 ◽  
Vol 4 (3) ◽  
pp. 259-262
Author(s):  
M. Shah Alam Bhuiyan ◽  
Yuji Ito . ◽  
Naotaka Tanaka . ◽  
Golam Sadik . ◽  
Kiyotaka Fujita . ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Sorting ◽  
Vacuolar Protein Sorting ◽  
Isolation And Characterization ◽  
Vacuolar Protein

MP005INCREASED LYSOSOMAL DEGRADATION OF AQP2 IN MPKCCDC14 CELLS WITH KNOCKDOWN OF VACUOLAR PROTEIN SORTING-ASSOCIATED PROTEIN 35

2016 ◽  
Vol 31 (suppl_1) ◽  
pp. i345-i345
Author(s):  
Hyo-Jung Choi ◽  
Mi Suk Lee ◽  
Dasom Kim ◽  
Eui-Jung Park ◽  
Yu-Jung Lee ◽  
...  
Keyword(s):  
Protein Sorting ◽  
Lysosomal Degradation ◽  
Vacuolar Protein Sorting ◽  
Vacuolar Protein

Vacuolar Protein Sorting in Yeast

1993 ◽  
pp. 329-338
Author(s):  
Bruce F. Horazdovsky ◽  
Todd R. Graham ◽  
Scott D. Emr
Keyword(s):  
Protein Sorting ◽  
Vacuolar Protein Sorting ◽  
Vacuolar Protein
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