Characterization of substrates that have a differential effect on Saccharomyces cerevisiae protein kinase A holoenzyme activation.

ABSTRACT: The specificity in phosphorylation by kinases is determined by the molecular recognition of the peptide target sequence. In Saccharomyces cerevisiae, the protein kinase A (PKA) specificity determinants are less studied than in mammalian PKA. The catalytic turnover numbers of the catalytic subunits isoforms Tpk1 and Tpk2 were determined, and both enzymes are shown to have the same value of 3 s(-1). We analyze the substrate behavior and sequence determinants around the phosphorylation site of three protein substrates, Pyk1, Pyk2, and Nth1. Nth1 protein is a better substrate than Pyk1 protein, and both are phosphorylated by either Tpk1 or Tpk2. Both enzymes also have the same selectivity toward the protein substrates and the peptides derived from them. The three substrates contain one or more

SUBMITTER: Galello F 

PROVIDER: S-EPMC2943320 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature