title: The effect of cAMP and cGMP on the activity and substrate specificity of protein kinase A from methylotrophic yeast Pichia pastoris.
abstract: Cyclic AMP dependent protein kinase (PKA) from Pichia pastoris yeast cells was found to be activated by either cAMP or cGMP. Analogs of cAMP such as 8-chloro-cAMP and 8-bromo-cAMP were as potent as cAMP in PKA activation while N6,2'-O-dibutyryl-cAMP did not stimulate the enzyme activity. It was shown that protamine sulfate was almost equally phosphorylated in the presence of 1-2 x 10(-6)M cAMP or cGMP while other substrates such as Kemptide, ribosomal protein S6, were phosphorylated to a lower extent in the presence of cGMP. It was demonstrated that pyruvate kinase is a substrate of PKA which co-purified with the P.pastoris enzyme. Moreover, pyruvate kinase was phosphorylated by PKA in the presence of cAMP and cGMP to comparable levels.
authors.affiliation: Department of Molecular Biology, Maria Curie-Skłodowska University, Lublin, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Frajnt
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Cytryńska
authors.forename: Teresa
authors.initials: T
authors.lastname: Jakubowicz
mesh_terms: D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D010766:Phosphorylation; D010843:Pichia / Q000201:enzymology* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D006152:Cyclic GMP