Protein Phosphatase 5, Catalytic Subunit (PPP5C)

A variety of biologic processes, such as cell signaling, transcription, and mitosis, are regulated by reversible protein phosphorylation at serine and threonine residues. The serine/threonine kinases are responsible for phosphorylation and the phosphatases are required for dephosphorylation. The PP5 cDNA was isolated by screening a human teratocarcinoma cDNA library at low stringency with a PP2B probe. By Northern blotting they observed a 2.3-kb mRNA in all tissues they examined. The predicted PP5 protein shares about 35 to 40% identity with other members of the superfamily and the N-terminal domain contains tetratricopeptide-like repeats found in several nuclear regulatory proteins. Recombinant PP5 was able to dephosphorylate serine residues and was shown to be sensitive to the tumor promoter okadaic acid.