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

Abstract

A novel member of human protein phosphatase 2C gene named PP2Cκ 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 PP2Cκ was widely expressed in normal human tissues. Transient transfection suggested that PP2Cκ was localized in the nucleus in AD293 cells. Recombinant Trx-His-PP2Cκ showed phosphatase activity toward p-nitrophenyl phosphate (pNPP), as well as oligopeptides containing phospho-threonine residues. Furthermore, the overexpression of PP2Cκ distinctly activated the heat shock transcription factor pathway in eukaryotic cells.