Activation of adenylate cyclase in cdc25 mutants of Saccharomyces cerevisiae.
The activation of adenylate cyclase by guanine nucleotides and 6-deoxyglucose was studied in membrane preparations from S. cerevisiae mutants lacking the CDC25 gene product. Adenylate cyclase from cdc25 ts membranes was activated by GTP and GppNHp in membranes from cells collected after glucose was exhausted from the medium. The activation was also observed in membranes from repressed cells at 2.5 mM Mg2+. It is also shown that 6-deoxyglucose can activate adenylate cyclase in the absence of CDC25 gene product. The relative amount of membrane-bound adenylate cyclase was drastically reduced in cdc25 ts membranes when subjected to the restrictive temperature, while no significant change was observed in the wild type. These data suggest that Cdc25 might not be required in certain conditions for the guanine nucleotide exchange reaction in Ras and that it might be implicated in anchoring the Ras/adenylate cyclase system to the plasma membrane.
Pardo
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LA
Departamento de Biología Funcional, Universidad de Oviedo, Spain.
Lazo
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PS
Ramos
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S
D000262:Adenylyl Cyclases / Q000378:metabolism*; D002451:Cell Compartmentation; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002462:Cell Membrane / Q000201:enzymology; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000494:pharmacology; D004789:Enzyme Activation; D005656:Fungal Proteins / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006150:Guanine Nucleotides / Q000378:metabolism; D007700:Kinetics; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D020666:ras-GRF1
C542351:CDC25 protein, S cerevisiae; D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D006150:Guanine Nucleotides; D029701:Saccharomyces cerevisiae Proteins; D020666:ras-GRF1; D003847:Deoxyglucose; D019204:GTP-Binding Proteins; D016283:Proto-Oncogene Proteins p21(ras); D000262:Adenylyl Cyclases; D005947:Glucose; C037904:6-deoxyglucose