Evidence for Involvement of Protein Kinase C in Germinal Vesicle Breakdown in Chaetopterus: (protein kinase C/phorbol ester/oocyte maturation).

We have examined the possible involvement of protein kinase C (C-kinase) in the initiation of germinal vesicle breakdown (GVBD) in Chaetopterus oocytes. Two tumor-promoting phorbol esters (phorbol-12, 13-dibezoate and 12-0-tetradecanoylphorbol-13-acetate [TPA]) and a permeant diacylglycerol (1-oleoyl-2-acetylglycerol), potent activators of C-Kinase, triggered GVBD. Two other phorbol esters (phorbol-13-monoacetate and 4α-phorbol-12, 13-didecanoate), which do not activate C-kinase, were inactive.