This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.106.101964v1 93/3/886    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kotani, N. Articles by Oiwa, K. Search for Related Content PubMed PubMed Citation Articles by Kotani, N. Articles by Oiwa, K.

Mechanical Properties of Inner-Arm Dynein-F (Dynein I1) Studied With In Vitro Motility Assays

Norito Kotani ^*, Hitoshi Sakakibara , Stan A. Burgess , Hiroaki Kojima  and Kazuhiro Oiwa ^* 

^* Graduate School of Life Science, University of Hyogo, Harima Science Park City, Hyogo 6781297, Japan; Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka, Nishi-ku, Kobe 6512492, Japan; and Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom

Correspondence: Address reprint requests to Kazuhiro Oiwa, oiwa{at}nict.go.jp.

Inner-arm dynein-f of Chlamydomonas flagella is a heterodimeric dynein. We performed conventional in vitro motility assays showing that dynein-f translocates microtubules at the comparatively low velocity of 1.2 µm/s. From the dependence of velocity upon the surface density of dynein-f, we estimate its duty ratio to be 0.6–0.7. The relation between microtubule landing rate and surface density of dynein-f are well fitted by the first-power dependence, as expected for a processive motor. At low dynein densities, progressing microtubules rotate erratically about a fixed point on the surface, at which a single dynein-f molecule is presumably located. We conclude that dynein-f has high processivity. In an axoneme, however, slow and processive dynein-f could impede microtubule sliding driven by other fast dyneins (e.g., dynein-c). To obtain insight into the in vivo roles of dynein-f, we measured the sliding velocity of microtubules driven by a mixture of dyneins -c and -f at various mixing ratios. The velocity is modulated as a function of the ratio of dynein-f in the mixture. This modulation suggests that dynein-f acts as a load in the axoneme, but force pushing dynein-f molecules forward seems to accelerate their dissociation from microtubules.

This article has been cited by other articles:

				K. H. Bui, H. Sakakibara, T. Movassagh, K. Oiwa, and T. Ishikawa Molecular architecture of inner dynein arms in situ in Chlamydomonas reinhardtii flagella J. Cell Biol., November 25, 2008; 183(5): 923 - 932. [Abstract] [Full Text] [PDF]