ハヤシ シュウイチ
  林 周一
   所属   川崎医科大学  医学部 基礎医学 解剖学
   職種   准教授
論文種別 原著
言語種別 英語
査読の有無 査読あり
表題 Bending-induced switching of dynein activity in elastase-treated axonemes of sea urchin sperm: roles of Ca2+ and ADP.
掲載誌名 正式名:Cell Motility and the Cytoskeleton
掲載区分国外
巻・号・頁 66(5),292-301頁
著者・共著者 Hayashi, S. and Shingyoji, C.
発行年月 2009
概要 Flagellar beating is caused by microtubule sliding, driven by the activity of dynein, between adjacent two of the nine doublet microtubules. An essential process in the regulation of dynein is to alternate its activity (switching) between the two sides of the central pair microtubules. The switching of dynein activity can be detected, in an in vitro system using elastase-treated axonemes of sea urchin sperm flagella, as a reversal of the relative direction of ATP-induced sliding between the two bundles of doublets at high Ca(2+) (10(-4) M) at pH 7.8-8.0. The reversal is triggered by externally applied bending of the doublet bundle. However, the mechanism of this bending-induced reversal (or backward sliding) remains unclear. To understand how the switching of dynein activity in flagella can be induced by bending, we studied the roles of ADP, which is an important factor for the dynein motile activity, and of Ca(2+) in the bending-induced reversal of microtubule sliding between two bundles of doublets at pH 7.5 and 7.2. We found that the reversal of sliding direction was induced regardless of the concentrations of Ca(2+) at low pH, but occurred more frequently at low Ca(2+) (<10(-9) M) than at high Ca(2+). At pH 7.5, an application of ADP increased the frequency of occurrence of backward sliding at high as well as low concentrations of Ca(2+). The results indicate that ADP-dependent activation of dynein, probably resulting from ADP-binding to dynein, is involved in the regulation of the bending-induced switching of dynein activity in flagella.