title: Protein kinase C activity in mouse eggs regulates gamete membrane interaction.
abstract: Gamete membrane interaction is critical to initiate the development of a new organism. The signaling pathways governing this event, however, are poorly understood. In this report, we provide the first evidence that protein kinase C activity in mouse eggs plays a crucial role in the regulation of this process. Stimulating PKC activity in mouse eggs by phorbol 12-myristate 13-acetate (PMA) drastically inhibited the egg's membrane ability to bind and fuse with sperm. Surprisingly, this significant reduction of gamete membrane interaction was also observed in eggs treated with the PKC inhibitors staurosporine and calphostin c. In further analysis, we found that while no change of egg actin cytoskeleton was detected after either PMA or calphostin c treatment, the structural morphology of egg surface microvilli was severely altered in the PMA-treated eggs, but not in the calphostin c-treated eggs. Moreover, sperm, which bound but did not fuse with the eggs treated with the anti-CD9 antibody KMC8, were liberated from the egg membrane after PMA, but not calphostin c, treatment. Taken together, these results suggest that egg PKC may be precisely balanced to regulate gamete membrane interaction in a biphasic mode, and this biphasic regulation is executed through two different mechanisms.
authors.affiliation: Department of Biological Sciences, Marshall University, Huntington, WV 25755, USA.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Akabane
authors.forename: Jun
authors.initials: J
authors.lastname: Fan
authors.forename: Xuehai
authors.initials: X
authors.lastname: Zheng
authors.forename: Guo-Zhang
authors.initials: GZ
authors.lastname: Zhu
mesh_terms: D000199:Actins / Q000648:ultrastructure; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD; D002462:Cell Membrane / Q000502:physiology*; D003599:Cytoskeleton / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors; D051379:Mice; D008813:Mice, Inbred ICR; D008871:Microvilli / Q000648:ultrastructure; D009281:Naphthalenes / Q000494:pharmacology; D010063:Ovum / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D019311:Staurosporine / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D060245:Tetraspanin 29
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C554870:Cd9 protein, mouse; D008562:Membrane Glycoproteins; D009281:Naphthalenes; D047428:Protein Kinase Inhibitors; D060245:Tetraspanin 29; C061465:calphostin complex; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate