Molecular mechanisms of the regulation of flagellar and cilliary movements.

Takahashi指出，海胆精子鞭毛轴丝经弹性酶处理后，在100微米的三磷酸腺苷作用下，其滑动速度在高钙和低钙浓度下是不同的。海胆精子鞭毛打动的表观滑动速度随拍频的变化而变化，表明滑动速度不受ATP浓度的影响。为了研究马达蛋白的分子机制，丰岛开发了一种新的体外运动性测试系统，使我们能够在特定位置持有马达蛋白。Ogawa建立的目的是生产编码在BaculoGold系统中表达的看似正确的动力蛋白运动域的cDNA。神谷分离出缺乏不同动力蛋白重链的新衣藻突变体，从而明确了它们的功能。Mohri研究了不同动物鞭毛和纤毛外臂动力蛋白的分子形态，发现原生动物的动力蛋白是三头的，而其他动物的动力蛋白是两头的。用胰凝乳酶消化的电泳分析表明，在轴突四膜虫(Nakamura)中，α-微管蛋白亚型(A5)位于动力蛋白臂附近。根据稻叶的说法，蛋白酶体位于从鞭毛轴丝向质膜延伸的突起处。在鞭毛运动的调控方面，森泽对相关蛋白质进行了纯化，然后进行了精子运动的启动、激活和精子的趋化作用的cdna克隆。Okuno证明，哺乳动物精子运动的激活与微管滑动速度的变化、微管之间的抑制和蛋白质的磷酸化密切相关。Nakaoka证明在含有cGMP的复活介质中，草履虫纤毛皮质片中的异时波被重建。环状AMP依赖的29 kDa和65 kDa的磷酸化是控制草履虫纤毛跳动方向的关键(

Takahashi showed that sliding velocities of sea urchin sperm flagellar axonemes, which were treated with elastase and reactivated at 100 muM ATP, were shown to be different in high and low calcium concentrations. Apparent sliding velocity of beating sea urchin sperm flagella was changed with changing the beat frequency, indicating that the sliding velocity is not determined with ATP concentration (Shingyoji). To study the molecular mechanism of motor proteins, Toyoshima has developed a novel in vitro motility assay system that allows us to hold motor proteins at specific site. Ogawa established to produce cDNA encoding the plausible dynein motor domain which is expressed in BaculoGold system. Kamiya isolated new Chlamydomonas mutants lacking different dynein heavy chains and thereby made clear their functions. Molecular shape of the outer arm dynein in flagella and cilia was surveyed among various animals by Mohri who showed the dynein in protists was three-headed, whereas that in other animals was two-headed. Electrophoretic analysis using chymotrypsin digestion has suggested that the alpha-tubulin isoform (a5) is located near dynein arms in Tetrahymena axonemes (Nakamura). According to Inaba, proteasomes are located at the projection extending from flagellar axoneme toward plasma membrance. Concerning the regulation of flagellar movements, Morisawa carried out purification of related proteins and then cDNA cloning in regard to the initiation, activation of sperm motility and chemotaxisof spermatozoa. Okuno demonstrated that the activation of mammalian sperm motility is tightry coupled with the changes in sliding velocity of microtubules, restaint between the microtubules and protein phosphorylation. Nakaoka showed that metachronal waves in ciliated cortical sheet of Paramecium was reconstituted in the reactivation medium containing cGMP.Cyclic AMP dependent phosphorylation of 29kDa and 65kDa were essential for controlling ciliary beating direction in Paramecium (