Activation state of protein kinase A as measured in permeabilised Saccharomyces cerevisiae cells correlates with PKA-controlled phenotypes in vivo.
Protein kinase A (PKA) activity was measured in situ in permeabilised Saccharomyces cerevisiae cells in the absence and the presence of cAMP. Four strains genetically predicted to have differential PKA-dependent phenotypes were used: a wild-type strain and a strain containing a bcy1-14 mutation (with almost constitutively active PKA), and the same strains with overexpression of the wild-type or mutant BCY1 gene, respectively. Cells were grown on galactose or glucose. The measured phenotypic characteristics were: trehalose and glycogen levels and the activity of a reporter gene under control of the NTH1 promoter. The 'endogenous' PKA activity (measured in situ in the absence of cAMP) showed the best correlation with the PKA-dependent phenotypes determined in vivo. We propose that this parameter offers a good estimate for the degree of activation of PKA in vivo.
Portela
Paula
P
Departamento de Qui;mica Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, 1428, Buenos Aires, Argentina.
Van Dijck
Patrick
P
Thevelein
Johan M
JM
Moreno
Silvia
S
D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D005690:Galactose / Q000378:metabolism; D017930:Genes, Reporter; D005947:Glucose / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000502:physiology; D013379:Substrate Specificity
D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D005947:Glucose; D005690:Galactose