title: Guanine nucleotide activation of, and competition between, RAS proteins from Saccharomyces cerevisiae.
abstract: In the yeast Saccharomyces cerevisiae, yeast RAS proteins are potent activators of adenylate cyclase. In the present work we measured the activity of adenylate cyclase in membranes from Saccharomyces cerevisiae which overexpress this enzyme. The response of the enzyme to added RAS2 proteins bound with various guanine nucleotides and their analogs suggests that RAS2 proteins are active in their GTP-bound form and are virtually inactive in their GDP-bound form. Also, active RAS2 protein is not inhibited by inactive RAS2, suggesting that the inactive form does not compete with the active form in binding to its effector.
authors.forename: J
authors.initials: J
authors.lastname: Field
authors.forename: D
authors.initials: D
authors.lastname: Broek
authors.forename: T
authors.initials: T
authors.lastname: Kataoka
authors.forename: M
authors.initials: M
authors.lastname: Wigler
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D004789:Enzyme Activation; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000494:pharmacology*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D013873:Thionucleotides / Q000494:pharmacology; D018631:ras Proteins
chemical_list: D005656:Fungal Proteins; D006150:Guanine Nucleotides; D029701:Saccharomyces cerevisiae Proteins; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D006165:Guanylyl Imidodiphosphate; C023427:guanosine 5'-O-(2-thiodiphosphate); D006160:Guanosine Triphosphate; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins; D000262:Adenylyl Cyclases