INSERM U935/Université Paris Sud/AP-HP, Histologie-Embryologie-Cytogénétique, Hôpital Antoine Béclère, 92141 Clamart, France.
Cell Calcium. 2012 Nov;52(5):388-96. doi: 10.1016/j.ceca.2012.06.006. Epub 2012 Jul 10.
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.
在所有物种中，受精都会引发卵子内细胞游离钙（Cai）的快速和短暂增加，但精子和卵子相互作用后如何产生这种信号尚未得到明确描述。在海胆中，涉及酪氨酸激酶和 PLCγ 的信号通路被认为是受精 Cai 信号的起源。我们在这里报告，海胆 PLCγ 的 SH2 结构域的注射以竞争性方式抑制内源性 PLCγ，改变受精 Cai 波的幅度和持续时间，但不会使其消失。我们的结果表明，PLCγ 与 cADPr 途径和 Gαq 型 G 蛋白一起作用，引发受精 Cai 波，并增强 PLCγ 在有丝分裂和胞质分裂中的关键作用。
