title: Feedback regulation of Ras2 guanine nucleotide exchange factor (Ras2-GEF) activity of Cdc25p by Cdc25p phosphorylation in the yeast Saccharomyces cerevisiae.
abstract: Ras-GEF Cdc25p has been found to be hyperphosphorylated upon glucose addition. This work provides evidence indicating that PKA activity positively regulates the degree of Cdc25p phosphorylation, and that the intracellular association of Cdc25p and Ras2p is independent of PKA activity. In vitro experiments revealed that the Ras2-GEF activity of Cdc25p is inhibited by Cdc25p phosphorylation. These data suggest a negative feedback mechanism by which intracellular cAMP synthesis is inhibited by PKA through Cdc25p phosphorylation.
authors.affiliation: Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Nankai District, Tianjin, PR China. dongjianbio@tju.edu.cn
authors.forename: Dong
authors.initials: D
authors.lastname: Jian
authors.forename: Zhang
authors.initials: Z
authors.lastname: Aili
authors.forename: Bai
authors.initials: B
authors.lastname: Xiaojia
authors.forename: Zhao
authors.initials: Z
authors.lastname: Huansheng
authors.forename: Hu
authors.initials: H
authors.lastname: Yun
mesh_terms: D002244:Carbon / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D025461:Feedback, Physiological; D047468:Immunoprecipitation; D042541:Intracellular Space / Q000378:metabolism; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism; D020666:ras-GRF1 / Q000378:metabolism*
chemical_list: C542351:CDC25 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D020666:ras-GRF1; D002244:Carbon; D017868:Cyclic AMP-Dependent Protein Kinases; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins