|
|
|
|
|
||
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 112, Issue 6 877-886, Copyright © 1999 by Company of Biologists
JOURNAL ARTICLES |
Y Fukui, T Kitanishi-Yumura and S Yumura
Cell and Molecular Biology, Northwestern University Medical School, Chicago, Illinois, USA. y-fukui@nwu.edu
While the treadmilling and retrograde flow of F-actin are believed to be responsible for the protrusion of leading edges, little is known about the mechanism that brings the posterior cell body forward. To elucidate the mechanism for global cell locomotion, we examined the organizational changes of filamentous (F-) actin in live Dictyostelium discoideum. We labeled F-actin with a trace amount of fluorescent phalloidin and analyzed its dynamics in nearly two-dimensional cells by using a sensitive, high-resolution charge-coupled device. We optically resolved a cyclic mode of tightening and loosening of fibrous cortical F-actin and quantitated its flow by measuring temporal and spatial intensity changes. The rate of F-actin flow was evaluated with respect to migration velocity and morphometric changes. In migrating monopodial cells, the cortical F-actin encircling the posterior cell body gradually accumulated into the tail end at a speed of 0.35 microm/minute. We show qualitatively and quantitatively that the F-actin flow is closely associated with cell migration. Similarly, in dividing cells, the cortical F-actin accumulated into the cleavage furrow. Although five times slower than the wild type, the F-actin also flows rearward in migrating mhcA- cells demonstrating that myosin II ('conventional' myosin) is not absolutely required for the observed dynamics of F-actin. Yet consistent with the reported transportation of ConA-beads, the direction of observed F-actin flow in Dictyostelium is conceptually opposite from a barbed-end binding to the plasma membrane. This study suggests that the posterior end of the cell has a unique motif that tugs the cortical actin layer rearward by means of a mechanism independent from myosin II; this mechanism may be also involved in cleavage furrow formation.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  D. R. Soll, D. Wessels, S. Kuhl, and D. F. Lusche How a Cell Crawls and the Role of Cortical Myosin II Eukaryot. Cell, September 1, 2009; 8(9): 1381 - 1396. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Gardet, M. Breton, G. Trugnan, and S. Chwetzoff Role for Actin in the Polarized Release of Rotavirus J. Virol., May 1, 2007; 81(9): 4892 - 4894. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Jurado, J. R. Haserick, and J. Lee Slipping or Gripping? Fluorescent Speckle Microscopy in Fish Keratocytes Reveals Two Different Mechanisms for Generating a Retrograde Flow of Actin Mol. Biol. Cell, February 1, 2005; 16(2): 507 - 518. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. de la Roche, A. Mahasneh, S.-F. Lee, F. Rivero, and G. P. Cote Cellular Distribution and Functions of Wild-Type and Constitutively Activated Dictyostelium PakB Mol. Biol. Cell, January 1, 2005; 16(1): 238 - 247. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Yumura Myosin II dynamics and cortical flow during contractile ring formation in Dictyostelium cells J. Cell Biol., July 9, 2001; 154(1): 137 - 146. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Yoshida and K. Inouye Myosin II-dependent cylindrical protrusions induced by quinine in Dictyostelium: antagonizing effects of actin polymerization at the leading edge J. Cell Sci., January 6, 2001; 114(11): 2155 - 2165. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Henson, T. M. Svitkina, A. R. Burns, H. E. Hughes, K. J. MacPartland, R. Nazarian, and G. G. Borisy Two Components of Actin-based Retrograde Flow in Sea Urchin Coelomocytes Mol. Biol. Cell, December 1, 1999; 10(12): 4075 - 4090. [Abstract] [Full Text]
|
|
