Studies on cell signaling for regulating sperm chemotaxis

海鞘精子趋化和激活的研究：1）用NMR和MS/MS方法测定了海鞘卵中精子激活和吸引因子（SAAF）的分子结构。该因子是新的类固醇：（3R，4 R，7 R，25 S）-3，4，7，26-四羟基胆甾烷-3，26-二硫酸盐。合成了甾体化合物，并证明了纳摩尔浓度的甾体化合物可以激活和吸引海鞘精子。2)在精子趋化性的细胞信号转导中，研究表明stor-operated钙通道在精子趋化性中起着关键作用。此外，数值研究表明，两种不同的策略导致精子在海鞘和管水母中的趋化性。3)在细胞中，激活海鞘精子的信号传导，已经证明钙/钙调素/钙调素激酶系统激活K^+通道，由此产生的膜超极化引起cAMP增加，从而通过轴丝蛋白的磷酸化激活精子运动。4)在对太平洋鲱精子激活的研究中，阐明了反向Na^+/Ca^<2+>交换体的参与。5)在鲑科鱼类精子运动启动的细胞信号转导中，对cAMP依赖的蛋白激酶催化亚基进行了表征。此外，15 kDa的蛋白质，这是已知的是必不可少的鞭毛运动的启动，被纯化，并进行了表征。精子顶体反应是世界上首次在文昌鱼中发现的，而GTP锚定蛋白参与顶体反应也是首次在贻贝中发现。

On the studies of sperm chemotaxis and activation in the ascidians Ciona 1) molecular structure of sperm-activating and -attracting factor (SAAF) originated from the eggs was determined using NMR and MS/MS methods. The factor is the novel steroid : (3R,4R,7R,25S)-3,4,7,26-tetrahydroxycholestane-3,26-disulfate. The steroid was synthesized and it was demonstrated that nanomolar concentration could activate and attract the ascidian sperm. 2) In the cell signaling for the sperm chemotaxis, it was demonstrated that stor-operated calcium channel plays key role for the phenomenon. Furthermore, a numerical studies showed that two different strategies cause sperm chemotaxis in the ascidians and siphonophores. 3) In the cell, signaling for the activation of ascidian sperm, It was demonstrated that calcium/calmodulin/calmoduline kinase system activates K^+ channel and resulting membrane hyperpolarization causes cAMP increase, resulting in the activation of sperm motility through phosphorylation of axonemal proteins. 4) On the studies of sperm activation in the Pacific hering Clupea pallasi, participation of reversed Na^+/Ca^<2+> exchanger was clarified. 5) On the cell signaling for the, initiation of sperm motility in the salmonid fish, cAMP-dependent protein kinase catalytic subunit was characterized. Furthermore, the 15kDa protein, which is known to be indispensable for the initiation of flagellar motility, was purified, and it's characterized. The acrosome reaction of spermatozoa was first found in amphioxus in the world, and participation of GTP-anchored protein in the acrosome reaction was also first found the mussel, Mytilus edulis.