spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sugi, H.
Right arrow Articles by Chaen, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sugi, H.
Right arrow Articles by Chaen, S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?
The Journal of Experimental Biology 206, 1971-1976 (2003)
doi: 10.1242/jeb.00239

Review Article

Force–velocity relationships in actin–myosin interactions causing cytoplasmic streaming in algal cells

Haruo Sugi1,* and Shigeru Chaen2

1 Department of Physiology, School of Medicine, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
2 Department of Applied Physics, College of Humanities and Science, Nihon University, Setagaya-ku,Tokyo 156-8550, Japan

* Author for correspondence (e-mail: sugi{at}med.teikyo-u.ac.jp)

Accepted 15 January 2003

Cytoplasmic streaming in giant internodal cells of green algae is caused by ATP-dependent sliding between actin cables fixed on chloroplast rows and cytoplasmic myosin molecules attached to cytoplasmic organelles. Its velocity (>=50 µm s-1) is many times larger than the maximum velocity of actin–myosin sliding in muscle. We studied kinetic properties of actin–myosin sliding causing cytoplasmic streaming in internodal cell preparations of Chara corallina, into which polystyrene beads, coated with cytoplasmic myosin molecules, were introduced. Constant centrifugal forces directed opposite to the bead movement were applied as external loads. The steady-state force–velocity (P–V) curves obtained were nearly straight, irrespective of the maximum isometric force generated by cytoplasmic myosin molecules, indicating a large duty ratio of cytoplasmic myosin head. The large velocity of cytoplasmic streaming can be accounted for, at least qualitatively, by assuming a mechanically coupled interaction between cytoplasmic myosin heads as well as a large distance of unitary actin–myosin sliding.

Key words: cytoplasmic streaming, actin–myosin sliding, cytoplasmic myosin, actin cables, centrifuge microscope, Nitellopsis obtusa, Chara corallina


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
R. E. Goldstein, I. Tuval, and J.-W. van de Meent
From the Cover: Microfluidics of cytoplasmic streaming and its implications for intracellular transport
PNAS, March 11, 2008; 105(10): 3663 - 3667.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
R. K. Suarez
Shaken and stirred: muscle structure and metabolism
J. Exp. Biol., June 15, 2003; 206(12): 2021 - 2029.
[Abstract] [Full Text] [PDF]


© The Company of Biologists Ltd 2003