Abstract

Poster Presentations

Day 3, June 12（Wed.）　　Room P1 (Multipurpose Hall)・Room P2 (Conference Room 101+102)

Protein phosphorylation plays an important role in cell signaling, and abnormal phosphorylation can cause various diseases. Although there are more than 500 protein kinases in humans, few of them are known for their functions and substrate selectivity. Therefore, even now that phosphoproteome analysis has enabled large-scale identification of phosphorylation sites in the human proteome, there is a problem that many data cannot be utilized due to lack of kinase-substrate information. In this study, with the aim of developing a method for selectively and simultaneously measuring the activity of all kinases (kinomes) in human cells, we designed non-endogenous substrate peptides that can distinguish kinase isoforms with very similar substrate motifs, and evaluated their selectivity and sensitivity. First, in vitro kinase assays were performed on HeLa cell lysate using 5 recombinant human protein kinase C (PKC) isoforms to obtain in vitro kinase-substrate information. Based on the results, we synthesized substrate peptide candidates that are considered to be highly selective and highly sensitive for each PKC isoforms. Evaluated by in vitro assays using 5 recombinant kinases, several artificial substrate peptides were found that were selectively phosphorylated by specific isoforms.

---