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

Abstract
The protein phosphatases PP1c, PP2Ac and PP2Cα are shown to dephosphorylate protein kinase Cδ (PKCδ) in vitro; of these PP2Ac displayed the highest specific activity towards PKCδ. The role of PP2Ac in the dephosphorylation of PKCδ 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 PKCδ could protect the enzyme from dephosphorylation by PP2Ac in vitro indicates that an additional input/factor is required for dephosphorylation in vivo.