Phorbol ester-induced translocation of PKC epsilon to the nucleus in fibroblasts: identification of nuclear PKC epsilon-associating proteins

We show that phorbol ester treatment of NIH 3T3 fibroblasts induces rapid translocation of PKCepsilon from a perinuclear site to the nucleus, extending findings in PC 12 and NG108-15 cells and in myocytes. We have immunoprecipitated the PKCepsilon from nuclei isolated from phorbol ester-treated fibroblasts and identified six proteins which associate with nuclear PKCepsilon. These have been characterised as matrin 3, transferrin, Rac GTPase activating protein 1, vimentin, beta-actin and annexin 11 by MALDI-TOF-MS. We have confirmed that these proteins associate with PKCepsilon by gel overlay and/or dot blotting assays. The role of these PKCepsilon-associating proteins in the nucleus and their interaction with PKCepsilon are considered. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.