Biomaterial Database

VPS27 controls vacuolar and endocytic traffic through a prevacuolar compartment in Saccharomyces cerevisiae. 1995

R C Piper, and A A Cooper, and H Yang, and T H Stevens

Institute of Molecular Biology, University of Oregon, Eugene 97403-1229, USA.

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.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002268	Carboxypeptidases	Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.	Carboxypeptidase
D002451	Cell Compartmentation	A partitioning within cells due to the selectively permeable membranes which enclose each of the separate parts, e.g., mitochondria, lysosomes, etc.	Cell Compartmentations,Compartmentation, Cell,Compartmentations, Cell
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004705	Endocytosis	Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.	Endocytoses
D005656	Fungal Proteins	Proteins found in any species of fungus.	Fungal Gene Products,Fungal Gene Proteins,Fungal Peptides,Gene Products, Fungal,Yeast Proteins,Gene Proteins, Fungal,Peptides, Fungal,Proteins, Fungal
D005800	Genes, Fungal	The functional hereditary units of FUNGI.	Fungal Genes,Fungal Gene,Gene, Fungal
D006056	Golgi Apparatus	A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Golgi Complex,Apparatus, Golgi,Complex, Golgi
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein