Analysis of respiratory mutants reveals new aspects of the control of glycogen accumulation by the cyclin-dependent protein kinase Pho85p.
The PHO85 gene of Saccharomyces cerevisiae encodes a cyclin-dependent protein kinase that can interact with 10 different cyclins (Pcls). In conjunction with Pcl8p and Pcl10p, Pho85p phosphorylates and regulates glycogen synthase. Respiratory-deficient strains, such as coq3 mutants, have reduced glycogen stores and contain hyperphosphorylated and inactive glycogen synthase. We show here that pho85 coq3 mutants have dephosphorylated and active glycogen synthase yet do not maintain glycogen reserves. In contrast, deletion of PCL8 and PCL10 in the coq3 mutant background partially restores glycogen accumulation. This suggested the existence of inputs from Pho85p into glycogen storage, independent of Pcl8p and Pcl10p, and acting antagonistically.
Wilson
Wayne A
WA
Department of Biochemistry, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202-5122, USA. wwilson@iupui.edu
Wang
Zhong
Z
Roach
Peter J
PJ
D019069:Cell Respiration / Q000502:physiology*; D018844:Cyclin-Dependent Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D016213:Cyclins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D006003:Glycogen / Q000378:metabolism*; D024981:Glycogen Phosphorylase / Q000378:metabolism; D006006:Glycogen Synthase / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D010766:Phosphorylation; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014451:Ubiquinone / Q000172:deficiency
D016213:Cyclins; D005656:Fungal Proteins; C542192:PCL10 protein, S cerevisiae; C542193:PCL8 protein, S cerevisiae; C066824:PHO80 protein, S cerevisiae; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014451:Ubiquinone; D006003:Glycogen; D024981:Glycogen Phosphorylase; D006006:Glycogen Synthase; D018844:Cyclin-Dependent Kinases; C058605:PHO85 protein, S cerevisiae