Dephosphorylation of PKCδ by protein phosphatase 2Ac and its inhibition by nucleotides

The protein phosphatases PP1(c), PP2A(c) and PP2Calpha are shown to dephosphorylate protein kinase Cdelta (PKCdelta) in vitro; of these PP2A(c) displayed the highest specific activity towards PKCdelta. The role of PPA(c) in the dephosphorylation of PKCdelta in cells was supported by the demonstration that these proteins could be co-immunoprecipitated from NIH3T3 cells. However the observation that binding of Mg-ATP to PKCdelta could protect the enzyme from dephosphorylation by PP2A(c) in vitro indicates that an additional input/factor is required for dephosphorylation in vivo. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.