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Mol Cell Biol

Title:		Saccharomyces cerevisiae Mpt5p interacts with Sst2p and plays roles in pheromone sensitivity and recovery from pheromone arrest
Author(s):		Chen T; Kurjan J;
Address:		"Department of Microbiology and Molecular Genetics, College of Medicine, University of Vermont, Burlington 05405-0068, USA"
Journal Title:		Mol Cell Biol
Year:		1997
Volume:		17
Issue:		6
Page Number:		3429 - 3439
DOI:		10.1128/MCB.17.6.3429
ISSN/ISBN:		0270-7306 (Print) 1098-5549 (Electronic) 0270-7306 (Linking)
Abstract:		"SST2 plays an important role in the sensitivity of yeast cells to pheromone and in recovery from pheromone-induced G1 arrest. Recently, a family of Sst2p homologs that act as GTPase-activating proteins (GAPs) for G alpha subunits has been identified. We have identified an interaction between Sst2p and the previously identified Mpt5p by using the two-hybrid system. Loss of Mpt5p function resulted in a temperature-sensitive growth phenotype, an increase in pheromone sensitivity, and a defect in recovery from pheromone-induced G1 arrest, although the effects on pheromone response and recovery were mild in comparison to those of sst2 mutants. Overexpression of either Sst2p or Mpt5p promoted recovery from G1 arrest. Promotion of recovery by overexpression of Mpt5p required Sst2p, but the effect of overexpression of Sst2p was only partially dependent on Mpt5p. Mpt5p was also found to interact with the mitogen-activated protein kinase homologs Fus3p and Kss1p, and an mpt5 mutation was able to suppress the pheromone arrest and mating defects of a fus3 mutant. Because either mpt5 or cln3 mutations suppressed the fus3 phenotypes, interactions of Mpt5p with the G1 cyclins and Cdc28p were tested. An interaction between Mpt5p and Cdc28p was detected. We discuss these results with respect to a model in which Sst2p plays a role in pheromone sensitivity and recovery that acts through Mpt5p in addition to a role as a G alpha GAP suggested by the analysis of the Sst2p homologs"
Keywords:		"CDC28 Protein Kinase, S cerevisiae/metabolism Calcium-Calmodulin-Dependent Protein Kinases/metabolism Carrier Proteins/*metabolism Cell Cycle Fungal Proteins/*metabolism G1 Phase *GTPase-Activating Proteins *Mitogen-Activated Protein Kinases Models, Chemi;"
Notes:		"MedlineChen, T Kurjan, J eng GM40585/GM/NIGMS NIH HHS/ Research Support, U.S. Gov't, P.H.S. 1997/06/01 Mol Cell Biol. 1997 Jun; 17(6):3429-39. doi: 10.1128/MCB.17.6.3429"