Yeast Ysl2p, homologous to Sec7 domain guanine nucleotide exchange factors, functions in endocytosis and maintenance of vacuole integrity and interacts with the Arf-Like small GTPase Arl1p.
We previously described the isolation of ysl2-1 due to its genetic interaction with Delta ypt51/vps21, a mutant with a deletion of the coding sequence for the yeast Rab5 homolog, which regulates endocytic traffic between early and late endosomes. Here we report that Ysl2p is a novel 186.8-kDa peripheral membrane protein ... homologous to members of the Sec7 family. We provide multiple genetic and biochemical evidence for an interaction between Ysl12p and the Arf-like protein Arl1p, consistent with a potential function as an Arf guanine nucleotide exchange factor (GEF). The temperature-sensitive alleles ysl2-307 and ysl2-316 are specifically defective in ligand-induced degradation of Ste2p and alpha-factor and exhibit vacuole fragmentation directly upon a shift to 37 degrees C. In living cells, green fluorescent protein (GFP)-Ysl2p colocalizes with endocytic elements that accumulate FM4-64. The GFP-Ysl2p staining is sensitive to a mutation in VPS27 resulting in the formation of an aberrant class E compartment, but it is not affected by a sec7 mutation. Consistent with the idea that Ysl2p and Arl1p have closely related functions, Delta arl1 cells are defective in endocytic transport and in vacuolar protein sorting.
Mesh Terms:
ADP-Ribosylation Factors, Amino Acid Sequence, Base Sequence, Carboxypeptidases, Cathepsin A, Endocytosis, Endosomes, Fluorescent Dyes, Fungal Proteins, GTP Phosphohydrolases, Glycoside Hydrolases, Green Fluorescent Proteins, Guanine Nucleotide Exchange Factors, Intracellular Membranes, Luminescent Proteins, Membrane Proteins, Molecular Sequence Data, Mutation, Organic Anion Transporters, Sodium-Dependent, Pyridinium Compounds, Quaternary Ammonium Compounds, Sequence Analysis, Sequence Homology, Amino Acid, Symporters, Temperature, Vacuoles, beta-Fructofuranosidase
ADP-Ribosylation Factors, Amino Acid Sequence, Base Sequence, Carboxypeptidases, Cathepsin A, Endocytosis, Endosomes, Fluorescent Dyes, Fungal Proteins, GTP Phosphohydrolases, Glycoside Hydrolases, Green Fluorescent Proteins, Guanine Nucleotide Exchange Factors, Intracellular Membranes, Luminescent Proteins, Membrane Proteins, Molecular Sequence Data, Mutation, Organic Anion Transporters, Sodium-Dependent, Pyridinium Compounds, Quaternary Ammonium Compounds, Sequence Analysis, Sequence Homology, Amino Acid, Symporters, Temperature, Vacuoles, beta-Fructofuranosidase
Mol. Cell. Biol.
Date: Jul. 01, 2002
PubMed ID: 12052896
View in: Pubmed Google Scholar
Download Curated Data For This Publication
16300
Switch View:
- Interactions 4