Title: | Clathrin facilitates the internalization of seven transmembrane segment receptors for mating pheromones in yeast |
Author(s): | Tan PK; Davis NG; Sprague GF; Payne GS; |
Address: | "Department of Biological Chemistry, University of California at Los Angeles School of Medicine 90024" |
ISSN/ISBN: | 0021-9525 (Print) 1540-8140 (Electronic) 0021-9525 (Linking) |
Abstract: | "The role of clathrin in endocytosis of the yeast phermone receptors was examined using strains expressing a temperature-sensitive clathrin heavy chain. The yeast phermone receptors belong to the family of seven transmembrane segment, G-protein-coupled receptors. A rapid and reversible defect in uptake of radiolabeled alpha-factor pheromone occurred when the cells were transferred to the nonpermissive temperature. Constitutive, pheromone-independent internalization of newly synthesized a-factor phermone receptor was also rapidly inhibited in mutant strains at the nonpermissive temperature. In both cases residual endocytosis, 30-50% of wild-type levels, was detected in the absence of functional clathrin heavy chain. Once internalized, the a-factor receptor was delivered to the vacuole at comparable rates in chc1-ts and wild-type cells at the nonpermissive temperature. Clathrin heavy chain was also required for maximal uptake of a mutant a-factor receptor which is dependent on pheromone for internalization. In the presence of a-factor, the internalization rate of the mutant receptor in chc1-ts cells at the nonpermissive temperature was 2.5 times slower than the rate observed for endocytosis of the mutant receptor in wild-type cells. These experiments provide in vivo evidence that clathrin plays an important role in the endocytosis of the seven trans-membrane segment pheromone receptors in yeast" |
Keywords: | "Biological Transport Clathrin/biosynthesis/genetics/*metabolism Endocytosis GTP-Binding Proteins/metabolism *Genes, Fungal Genotype Kinetics Mating Factor Peptides/*metabolism Pheromones/*metabolism Pronase Receptors, Mating Factor Receptors, Peptide/gene;" |
Notes: | "MedlineTan, P K Davis, N G Sprague, G F Payne, G S eng GM-07185/GM/NIGMS NIH HHS/ GM-30027/GM/NIGMS NIH HHS/ GM12672/GM/NIGMS NIH HHS/ Comparative Study Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. 1993/12/01 J Cell Biol. 1993 Dec; 123(6 Pt 2):1707-16. doi: 10.1083/jcb.123.6.1707" |