Li Yang, Liu Ji-Hong
Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
Zhonghua Nan Ke Xue. 2002;8(5):367-70.
Protein kinase C (PKC) is localized in the equatorial segment and the principal piece of the tail of spermatozoa. Activator of PKC results in increasing flagellar motility of sperm that is blocked by PKC inhibitors such as staurosporine. A good correlation (r = 0.9, P < 0.001) is found between the content of PKC in sperm and sperm motility. Zona pellucida (ZP) stimulates the spermatozoa binding the acrosome reaction resulting in the release of hydrolytic enzymes and in the exposure of new membrane domains. ZP binding to receptors in the plasma membrane can regulate adenyl cyclase (AC) leading to elevation of cAMP and protein kinase A (PKA) activation. The PKA activates a voltage-dependent Ca2+ channel in the outer acrosomal membrane which releases Ca2+ from the interior of the acrosome to the cytosol. Activation of the PLC resulted from the rise in Ca2+ hydrolyze phosphatidyl inositol bisphosphate. The product activate PCK to open a voltage-dependent Ca2+ channel (L) in the plasma membrane, leading to the second (II) Ca2+ higher increase which result in membrane fusion and acrosome reaction. It is proposed that PKC would be involved in the regulation of motility and acrosome reaction of sperm.
蛋白激酶C（PKC）定位于精子的赤道段和尾部主段。PKC激活剂可增加精子鞭毛运动，而这种运动可被PKC抑制剂（如星形孢菌素）阻断。精子中PKC的含量与精子活力之间存在良好的相关性（r = 0.9，P < 0.001）。透明带（ZP）刺激精子结合并引发顶体反应，导致水解酶释放和新膜结构域暴露。ZP与质膜中的受体结合可调节腺苷酸环化酶（AC），导致cAMP升高和蛋白激酶A（PKA）激活。PKA激活顶体外膜中的电压依赖性Ca2+通道，使Ca2+从顶体内部释放到细胞质中。Ca2+升高导致磷脂酶C（PLC）激活，水解磷脂酰肌醇二磷酸。其产物激活蛋白激酶C（PCK），打开质膜中的电压依赖性Ca2+通道（L型），导致第二次（更高）Ca2+升高，从而引起膜融合和顶体反应。有人提出PKC参与精子运动和顶体反应的调节。
