Profile of protein kinase C isozymes and their possible role in mammalian egg activation

Western blot analysis was used to investigate protein kinase C (PKC) profile of rat eggs. The presence of eight PKC isozymes was demonstrated: conventional PKC α, β and γ; novel PKC δ, ε and μ; atypical PKC ζ and λ. PKC α was detected by RT-PCR as well. PKC translocation from the cytosol to the plasma membrane served as a marker for enzyme activation. Immunofluorescence confocal microscopy demonstrated a relatively uniform distribution of PKC α, βI, and βII throughout the cytosol of metaphase II arrested eggs. PKC accumulation at the plasma membrane was detected 5 min after exposure to 12-O-tetradecanoyl phorbol-13-acetate and increased with time, thus demonstrating activation of these PKCs.