Saccharomyces cerevisiae pyruvate kinase Pyk1 is PKA phosphorylation substrate in vitro.
Fractionation of Saccharomyces cerevisiae postribosomal extract on DEAE-cellulose revealed two fractions of cAMP-dependent protein kinase (PKA-1 and PKA-2). The presence of PKA in both fractions was confirmed by immunoblotting with anti-Bcy1 antibodies. Yeast pyruvate kinase Pyk1 identified by amino acid microsequencing analysis and immunoblotting with anti-Pyk1 antibodies copurified with the PKA-1 but not the -2 fraction. Pyk1 can be phosphorylated by yeast PKA in vitro in the presence of cAMP and cGMP. Two-dimensional gel electrophoretic analysis revealed four phosphorylated forms of Pyk1 modified by PKA. In phosphorylation of Pyk1 mainly the Tpk2 catalytic subunit of yeast PKA was involved.
Cytryńska
M
M
Department of Molecular Biology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland.
Frajnt
M
M
Jakubowicz
T
T
D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D015151:Immunoblotting; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011770:Pyruvate Kinase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D001426:Bacterial Proteins; D011770:Pyruvate Kinase; D017868:Cyclic AMP-Dependent Protein Kinases