Saccharomyces cerevisiae lacking Btn1p modulate vacuolar ATPase activity to regulate pH imbalance in the vacuole.
AuthorsPadilla-López S, Pearce DA
JournalJ Biol Chem
PubMed ID16423829
'The vacuolar H(+)-ATPase (V-ATPase) along with ion channels and transporters maintains vacuolar pH. V-ATPase ATP hydrolysis is coupled with proton transport and establishes an electrochemical gradient between the cytosol and vacuolar lumen for coupled transport of metabolites. Btn1p, the yeast homolog to human CLN3 that is defective in Batten disease, ... More
HEAT repeats mediate plasma membrane localization of Tor2p in yeast.
AuthorsKunz J, Schneider U, Howald I, Schmidt A, Hall MN
JournalJ Biol Chem
PubMed ID10973982
'The subcellular distribution of Tor1p and Tor2p, two phosphatidylinositol kinase homologs and targets of the immunosuppressive drug rapamycin in Saccharomyces cerevisiae, was analyzed. We found that Tor protein is peripherally associated with membranes. Subcellular fractionation and immunofluorescence studies showed that Tor1p and Tor2p associate with the plasma membrane and a ... More
Two separate signals act independently to localize a yeast late Golgi membrane protein through a combination of retrieval and retention.
AuthorsBryant NJ, Stevens TH
JournalJ Cell Biol
PubMed ID9015300
'The localization of proteins to late-Golgi membranes (TGN) of Saccharomyces cerevisiae is conferred by targeting motifs containing aromatic residues in the cytosolic domains of these proteins. These signals could act by directing retrieval from a post-Golgi compartment or by preventing exit from the TGN. To investigate the mechanism of localization ... More
Cvt19 is a receptor for the cytoplasm-to-vacuole targeting pathway.
AuthorsScott SV, Guan J, Hutchins MU, Kim J, Klionsky DJ
JournalMol Cell
PubMed ID11430817
Cvt19 is specifically required for the transport of resident vacuolar hydrolases that utilize the cytoplasm-to-vacuole targeting (Cvt) pathway. Autophagy (Apg) and pexophagy, processes that use the majority of the same protein components as the Cvt pathway, do not require Cvt19. Cvt19GFP is localized to punctate structures on or near the ... More
The newly identified yeast GRD genes are required for retention of late-Golgi membrane proteins.
AuthorsNothwehr SF, Bryant NJ, Stevens TH
JournalMol Cell Biol
PubMed ID8649377
Processing of A-ALP, a late-Golgi membrane protein constructed by fusing the cytosolic domain of dipeptidyl aminopeptidase A to the transmembrane and lumenal domains of alkaline phosphatase (ALP), serves as a convenient assay for loss of retention of late-Golgi membrane proteins in Saccharomyces cerevisiae. In this study, a large group of ... More
The VPS8 gene is required for localization and trafficking of the CPY sorting receptor in Saccharomyces cerevisiae.
AuthorsChen YJ, Stevens TH
JournalEur J Cell Biol
PubMed ID8864656
To better understand the process of protein sorting to the yeast vacuole, the VPS8 gene was identified and characterized. VPS8 encodes a membrane-associated hydrophilic protein of 135 kDa (Vps8p), which is required for the accurate sorting of the vacuolar hydrolase, carboxypeptidase Y (CPY). vps8 mutant cells missort and secrete CPY ... More
Ligand recognition and domain structure of Vps10p, a vacuolar protein sorting receptor in Saccharomyces cerevisiae.
AuthorsJørgensen MU, Emr SD, Winther JR
JournalEur J Biochem
PubMed ID10095782
Vp10p is a receptor that sorts several different vacuolar proteins by cycling between a late Golgi compartment and the endosome. The cytoplasmic tail of Vps10p is necessary for the recycling, whereas the lumenal domain is predicted to interact with the soluble ligands. We have studied ligand binding to Vps10p by ... More
Vma9p (subunit e) is an integral membrane V0 subunit of the yeast V-ATPase.
AuthorsCompton MA, Graham LA, Stevens TH
JournalJ Biol Chem
PubMed ID16569636
The Saccharomyces cerevisiae vacuolar proton-translocating ATPase (V-ATPase) is composed of 14 subunits distributed between a peripheral V1 subcomplex and an integral membrane V0 subcomplex. Genome-wide screens have led to the identification of the newest yeast V-ATPase subunit, Vma9p. Vma9p (subunit e) is a small hydrophobic protein that is conserved from ... More
Apg2 is a novel protein required for the cytoplasm to vacuole targeting, autophagy, and pexophagy pathways.
AuthorsWang CW, Kim J, Huang WP, Abeliovich H, Stromhaug PE, Dunn WA, Klionsky DJ
JournalJ Biol Chem
PubMed ID11382760
To survive starvation conditions, eukaryotes have developed an evolutionarily conserved process, termed autophagy, by which the vacuole/lysosome mediates the turnover and recycling of non-essential intracellular material for re-use in critical biosynthetic reactions. Morphological and biochemical studies in Saccharomyces cerevisiae have elucidated the basic steps and mechanisms of the autophagy pathway. ... More
Inactivation of the phosphoinositide phosphatases Sac1p and Inp54p leads to accumulation of phosphatidylinositol 4,5-bisphosphate on vacuole membranes and vacuolar fusion defects.
AuthorsWiradjaja F, Ooms LM, Tahirovic S, Kuhne E, Devenish RJ, Munn AL, Piper RC, Mayinger P, Mitchell CA
JournalJ Biol Chem
PubMed ID17392273
Phosphoinositides direct membrane trafficking, facilitating the recruitment of effectors to specific membranes. In yeast phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) isproposed to regulate vacuolar fusion; however, in intact cells this phosphoinositide can only be detected at the plasma membrane. In Saccharomyces cerevisiae the 5-phosphatase, Inp54p, dephosphorylates PtdIns(4,5)P2 forming PtdIns(4)P, a substrate for the ... More
A multispecificity syntaxin homologue, Vam3p, essential for autophagic and biosynthetic protein transport to the vacuole.
AuthorsDarsow T, Rieder SE, Emr SD
JournalJ Cell Biol
PubMed ID9245783
Protein transport in eukaryotic cells requires the selective docking and fusion of transport intermediates with the appropriate target membrane. t-SNARE molecules that are associated with distinct intracellular compartments may serve as receptors for transport vesicle docking and membrane fusion through interactions with specific v-SNARE molecules on vesicle membranes, providing the ... More
Retrieval of resident late-Golgi membrane proteins from the prevacuolar compartment of Saccharomyces cerevisiae is dependent on the function of Grd19p.
AuthorsVoos W, Stevens TH
JournalJ Cell Biol
PubMed ID9456318
The dynamic vesicle transport processes at the late-Golgi compartment of Saccharomyces cerevisiae (TGN) require dedicated mechanisms for correct localization of resident membrane proteins. In this study, we report the identification of a new gene, GRD19, involved in the localization of the model late-Golgi membrane protein A-ALP (consisting of the cytosolic ... More