Characterization of a novel human protein phosphatase 2C family member, PP2Cκ

A novel member of human protein phosphatase 2C gene named PP2C kappa was isolated from a human fetal brain cDNA library. The 2.0 kb cDNA encodes a 372 amino acid polypeptide with an intact protein phosphatase 2C (PP2C) catalytic domain. Reverse transcription-PCR (RT-PCR) revealed that the PP2C kappa was widely expressed in normal human tissues. Transient transfection suggested that PP2C kappa was localized in the nucleus in AD293 cells. Recombinant Trx-His-PP2C kappa showed phosphatase activity toward p-nitrophenyl phosphate (pNPP), as well as oligopeptides containing phospho-threonine residues. Furthermore, the overexpression of PP2C kappa distinctly activated the heat shock transcription factor pathway in eukaryotic cells.