The coatomer protein beta'-COP, a selective binding protein (RACK) for protein kinase Cepsilon.
Distinct subcellular localization of activated protein kinase C (PKC) isozymes is mediated by their binding to isozyme-specific RACKs (receptors for activated C-kinase). Our laboratory has previously isolated one such protein, RACK1, and demonstrated that this protein displays specificity for PKCbeta. We have recently shown that at least part of the PKCepsilon RACK-binding site on PKCepsilon lies within the unique V1 region of this isozyme (Johnson, J. A., Gray, M. O., Chen, C.-H., and Mochly-Rosen, D. (1996) J. Biol. Chem. 271, 24962-24966). Here, we have used the PKCepsilon V1 region to clone a PKCepsilon-selective RACK, which was identified as the COPI coatomer protein, beta'-COP. Similar to RACK1, beta'-COP contains seven repeats of the WD40 motif and fulfills the criteria previously established for RACKs. Activated PKCepsilon colocalizes with beta'-COP in cardiac myocytes and binds to Golgi membranes in a beta'-COP-dependent manner. A role for PKC in control of secretion has been previously suggested, but this is the first report of direct protein/protein interaction of PKCepsilon with a protein involved in vesicular trafficking.
Csukai
M
M
Department of Molecular Pharmacology, Stanford University School of Medicine, Stanford, California 94305-5332, USA.
Chen
C H
CH
De Matteis
M A
MA
Mochly-Rosen
D
D
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D020756:Coatomer Protein; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D006056:Golgi Apparatus / Q000201:enzymology; D007527:Isoenzymes / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D051381:Rats; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
D020756:Coatomer Protein; D005656:Fungal Proteins; D007527:Isoenzymes; D010455:Peptides; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C089602:Sec27 protein, S cerevisiae; C070301:peptide I; C497257:Prkce protein, rat; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon