Autophosphorylation and Cross-Phosphorylation of Protein Kinases from the Crenarchaeon Sulfolobus islandicus.

摘要: Protein phosphorylation, one of the most important post-translational modifications, regulates almost every cellular process. Although signal transduction by protein phosphorylation is extensively studied in Eukaryotes and Bacteria, knowledge this process archaea greatly lagging behind, especially for Ser/Thr/Tyr eukaryotic-like kinases (ePKs). So far, only a few studies on archaeal ePKs have been reported, which focused activities vitro, but their physiological functions interacting network are still largely unknown. In study, we systematically investigated autophosphorylation cross-phosphorylation from Sulfolobus islandicus REY15A using proteins expressed Escherichia coli or S. islandicus. vitro kinase assay showed that 7 out 11 putative activity. A Ser/Thr phosphatase, SiRe_1009, was able to dephosphorylate various autophosphorylated ePKs, confirming these kinases. Two SiRe_2030 SiRe_2056, homologs typical eukaryotic PKs involved peptide synthesis response stresses, exhibit highly efficient both themselves other ePKs. Overexpression vivo revealed elevated level either SiRe_1531 SiRe_2056 inhibited cell growth cells. Finally, proposed roles were discussed.