title: Regulation of MAPK function by direct interaction with the mating-specific Galpha in yeast.
abstract: The mating response of the budding yeast Saccharomyces cerevisiae is mediated by a prototypical heterotrimeric GTP-binding protein (G protein) and mitogen-activated protein kinase (MAPK) cascade. Although signal transmission by such pathways has been modeled in detail, postreceptor down-regulation is less well understood. The pheromone-responsive G protein alpha subunit (Galpha) of yeast down-regulates the mating signal, but its targets are unknown. We have found that Galpha binds directly to the mating-specific MAPK in yeast cells responding to pheromone. This interaction contributes both to modulation of the mating signal and to the chemotropic response, and it demonstrates direct communication between the top and bottom of a Galpha-MAPK pathway.
authors.affiliation: Department of Biological Sciences, Laboratory for Molecular Biology, University of Illinois at Chicago, 900 South Ashland Avenue (M/C 567), Chicago, IL 60607, USA.
authors.forename: Metodi V
authors.initials: MV
authors.lastname: Metodiev
authors.forename: Dina
authors.initials: D
authors.lastname: Matheos
authors.forename: Mark D
authors.initials: MD
authors.lastname: Rose
authors.forename: David E
authors.initials: DE
authors.lastname: Stone
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015536:Down-Regulation; D044385:GTP-Binding Protein alpha Subunits; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D044387:GTP-Binding Protein beta Subunits; D006153:Guanosine Diphosphate / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010675:Pheromones / Q000494:pharmacology; D010766:Phosphorylation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D044385:GTP-Binding Protein alpha Subunits; D044387:GTP-Binding Protein beta Subunits; D010675:Pheromones; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C067576:Ste4 protein, S cerevisiae; D006153:Guanosine Diphosphate; C075580:FUS3 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; C084293:GPA1 protein, S cerevisiae; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D020962:Heterotrimeric GTP-Binding Proteins