Zn2+-stimulation of sperm capacitation and of the acrosome reaction is mediated by EGFR activation.

摘要: Extracellular zinc regulates cell proliferation via the MAP1 kinase pathway in several types, and has been shown to act as a signaling molecule. The testis contains relatively high concentration of Zn(2+), required both early late stages spermatogenesis. Despite clinical significance this ion, its role mature sperm cells is poorly understood. In study, we characterized Zn(2+) capacitation acrosome reaction. Western blot analysis revealed presence ZnR GPR39 type cells. We previously demonstrated active epidermal growth factor receptor (EGFR) sperm, possible transactivation by direct activation G-protein coupled (GPCR), involvement reaction (AR). show here that activates EGFR during capacitation, which mediated trans-membrane adenylyl cyclase (tmAC), protein A (PKA), tyrosine kinase, Src. Moreover, addition capacitated caused further stimulation phosphatydil-inositol-3-kinase (PI3K) phosphorylation, leading AR. AR also occurred absence Ca(2+) incubation medium, tmAC, indicating GPCR. stimulated receptor, PKA, Src EGFR, well down-stream effectors PI3K, phospholipase C (PLC) (PKC). These data support for extracellular zinc, acting through ZnR, regulating multiple pathways