Calcium Release at Fertilization in Starfish Eggs Is Mediated by Phospholipase Cγ

• DOI: 10.1083/jcb.138.6.1303
• Publication Date: 2002-07-26T16:47:50Z
• Authors: David J. Carroll; Chodavarapu S. Ra...; Lisa M. Mehlmann; Serge Roche; Mark Terasaki; Laurinda A. Jaffe
• Keywords: Oocyte activation; Inositol trisphosphate

Although inositol trisphosphate (IP3) functions in releasing Ca2+ eggs at fertilization, it is not known how fertilization activates the phospholipase C that produces IP3. To distinguish between a role for PLCγ, which activated when its two src homology-2 (SH2) domains bind to an tyrosine kinase, and PLCβ, by G protein, we injected starfish with PLCγ SH2 domain fusion protein inhibits activation of PLCγ. In these eggs, release was delayed, or high concentration low sperm, completely inhibited. The PLCγSH2 specific inhibitor egg, since did inhibit PLCβ initiated serotonin 2c receptor, IP3 injection. Furthermore, injection mutated phosphotyrosine binding site, another (the phosphatase SHP2), fertilization. These results indicate during Cγ domain-mediated process stimulates production causes intracellular release.