Title: | "Isolation and characterization of SYS genes from yeast, multicopy suppressors of the functional loss of the transport GTPase Ypt6p" |
Address: | "Max Planck Institute for Biophysical Chemistry, Department of Molecular Genetics, Gottingen, Germany" |
ISSN/ISBN: | 0021-9533 (Print) 0021-9533 (Linking) |
Abstract: | "In Saccharomyces cerevisiae, the YPT6 gene encodes the homologue of the mammalian Rab6 protein found in the Golgi apparatus. Deletion of YPT6 in yeast produces a phenotype showing temperature-sensitive growth and partial missorting of the vacuolar enzyme, carboxypeptidase Y. To identify proteins that might: (1) interact with Ypt6p; or (2) act in the same pathway, we have isolated four multicopy suppressors, named SYS1, SYS2, SYS3 and SYS5, that can complement the temperature-sensitive growth phenotype of the ypt6 null mutant. On high expression, these genes are also able to partially suppress the missorting of carboxypeptidase Y.SYS2 on a multicopy plasmid suppresses in addition the temperature-sensitive phenotype of sec7-1, a mutant defective in transport between and from the Golgi compartment. Gene disruption of SYS1 and SYS2 did not result in significant growth defects. However, deletion of SYS1 and/or SYS2 in the ypt6 null mutant enhances defects in vacuolar protein sorting and in cell growth. Whereas protein secretion was not significantly affected in these mutants, the processing of alpha-factor precursor by the Kex2 protease was inhibited, suggesting a function of YPT6 and its null mutant suppressors in transport between the late Golgi and a prevacuolar, endosome-like compartment" |
Keywords: | "Amino Acid Sequence Carboxypeptidases/physiology Cathepsin A Cell Division/genetics Fungal Proteins/*genetics/*physiology GTP-Binding Proteins/*genetics/physiology Genes, Suppressor/*genetics/physiology Golgi Apparatus/genetics/physiology Mating Factor Mo;" |
Notes: | "MedlineTsukada, M Gallwitz, D eng Research Support, Non-U.S. Gov't England 1996/10/01 J Cell Sci. 1996 Oct; 109 ( Pt 10):2471-81. doi: 10.1242/jcs.109.10.2471" |