Tosca L, Glass R, Bronchain O, Philippe L, Ciapa B. PLCγ, G-protein of the Gαq type and cADPr pathway are associated to trigger the fertilization Ca2+ signal in the sea urchin egg.
Cell Calcium 2012;
52:388-96. [PMID:
22784667 DOI:
10.1016/j.ceca.2012.06.006]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 06/19/2012] [Accepted: 06/20/2012] [Indexed: 11/18/2022]
Abstract
In all species, fertilization triggers in the egg a rapid and transient increase of intracellular free calcium (Cai), but how this signal is generated following sperm and egg interaction has not been clearly characterised yet. In sea urchin, a signalling pathway involving tyrosine kinase and PLCγ has been proposed to be at the origin of the fertilization Cai signal. We report here that injection of src homology-2 (SH2) domains of the sea urchin PLCγ inhibits in a competitive manner the endogenous PLCγ, alters both the amplitude and duration of the fertilization Cai wave, but does not abrogate it. Our results suggest that PLCγ acts in conjunction with a cADPr pathway and G-proteins of the Gαq type to trigger the fertilization Cai wave, and reinforce a crucial role for PLCγ at mitosis and cytokinesis.
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