RESEARCH FOR MOLECULAR EVOLUTION OF PROTEIN KINASE C GENES OF PROTISTA EUGLENA GRACILIS ZAND ROLES OF THE KINASES.

点击翻译按钮获取中文摘要

Protein kinases play important roles in the process of cell signaling. The kinases have been classified into 5 groups on the claster analysis inferred from their amino acid sequences. The protein kinase A (PKA), protein kinase G (PKG) and protein kinase C (PKC) are clastered each other in a group, AGC-family. It is well-known especially on vertebrate that each AGC-family protein kinase shows various function in signaling processes. The genes coding PKA,PKG and PKC were not found in higher plants.The protein kinase gene from a higher plant, Brassica campestris L., were amplified by RT-PCR using several designed primers according to the consensus sequences along the kinase domain of the PKC.The amplified genes were subcloned and sequenced. Eight protein kinaes genes fragment were identified. They showed similarity to PKC,PVPK,S6-kinase or other type of orotein kinase genes such as MAPKK.The PKC homologue (bcpk 1) shows high simirality to the amino acid sequences of Trichoderma reesei PKC kinase domain (92.4%) and contains several conserved sequences specific in PKC sequence such as GGDLM (on subdomain V), FYAAE (on subdomain VIa) and TFCGT (on subdomain VIII). These results support that a higher plant, Brassica campestlis posseses signal transduction system concerning a PKC-like protein kinase. Further studies have been under progress.A PKC-like kinase was partially purified by DEAE-memsep chromatography. A PKC-like kinase fraction allowed to readt with partially purified nitrate recuctase (NR). Phosphorus group was transferred to NR protein strongly only when the reaction was performed in the presence of phosphatidylserine (PS), diacylglycerol (DG) and Ca^<2+> ion, indicative that NR-phosphorylation is likely to be involved by PKC-like protein kinase.