Recombinant C1b domain of PKCdelta triggers meiotic maturation upon microinjection in Xenopus laevis oocytes.
The C1 domains are 50 amino acid sequences present in protein kinase C (PKC) isozymes that are responsible for binding of phorbol esters and the lipid second messenger diacylglycerol (DAG). We found that bacterially expressed C1b domain of PKCdelta induces germinal vesicle breakdown (GVBD) when microinjected into Xenopus laevis oocytes. Injection of the C1b domain of PKCdelta significantly enhanced insulin- but not progesterone-induced maturation. Interestingly, the PKCdelta C1b domain markedly synergized with normal Ras protein to induce oocyte maturation when both proteins were co-injected in oocytes. Our results demonstrate that the purified C1b domain of PKCdelta is sufficient to promote meiotic maturation of X. laevis oocytes probably through activation of components of the insulin/Ras signaling pathway.
Aroca
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P
Department of Morphological Sciences, Faculty of Medicine, University of Murcia, E-30100 Murcia, Spain.
Santos
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E
Kazanietz
M G
MG
D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005260:Female; D007328:Insulin / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects*; D008845:Microinjections; D009154:Mutation; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development; D010703:Phorbol Esters / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D051745:Protein Kinase C-delta; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors; D014981:Xenopus; D018631:ras Proteins / Q000494:pharmacology; D018909:src Homology Domains / Q000235:genetics
D007328:Insulin; D007527:Isoenzymes; D010703:Phorbol Esters; D011994:Recombinant Proteins; D011374:Progesterone; D019869:Phosphatidylinositol 3-Kinases; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D018631:ras Proteins