Murase T, Roldan E R
Department of Development and Signalling, Babraham Institute, Cambridge, UK.
FEBS Lett. 1995 Mar 6;360(3):242-6. doi: 10.1016/0014-5793(95)00114-o.
Mouse spermatozoa stimulated with epidermal growth factor (EGF) or zona pellucida (ZP) experienced phosphatidylinositol 4,5-bisphosphate hydrolysis, diacylglycerol (DAG) generation and acrosomal exocytosis. The agonists showed additive effects but the action of EGF is likely to be mediated by a distinct receptor because maximal stimulation achieved with EGF was enhanced further by ZP. Generation of DAG and exocytosis stimulated by EGF were inhibited by tyrphostin A48, indicating that tyrosine kinase activity mediates EGF action. On the other hand, pertussis toxin did not affect the EGF-induced formation of DAG or exocytosis, ruling out the involvement of sperm Gi-like proteins. These results indicate that EGF could be an important co-factor in the initiation of exocytosis in spermatozoa.
用表皮生长因子（EGF）或透明带（ZP）刺激的小鼠精子经历了磷脂酰肌醇4,5-二磷酸水解、二酰基甘油（DAG）生成和顶体胞吐作用。这些激动剂显示出相加效应，但EGF的作用可能由一种独特的受体介导，因为ZP进一步增强了EGF所达到的最大刺激。酪氨酸磷酸化抑制剂A48抑制了EGF刺激的DAG生成和胞吐作用，表明酪氨酸激酶活性介导了EGF的作用。另一方面，百日咳毒素不影响EGF诱导的DAG形成或胞吐作用，排除了精子中类似Gi蛋白的参与。这些结果表明，EGF可能是精子胞吐作用起始过程中的一个重要辅助因子。
