The fully linked HTML version of this article has now been published.
JCS ePress
online publication date 29 Jan 2003
doi: 10.1242/jcs.00335
Research Article
Retrograde flow rate is increased in growth cones from myosin IIB knockout mice
Michael E. Brown
and
Paul C. Bridgman*
* Author for correspondence (e-mail: bridgmap{at}pcg.wustl.edu)
Growth cones of myosin-IIB-knockout mice have reduced outgrowth rates and traction force. There is a close relationship between traction force, retrograde flow and forward advance of growth cones. All three activities appear to be at least partially myosin dependent. Therefore, we have now tested for differences in retrograde flow rates between growth cones from myosin-IIB-knockout mice and their normal littermates. By placing nerve-growth-factor-coated silica beads on the surface of growth cones with laser tweezers, or by tracking GFP-myosin IIA spots, we found that the retrograde flow rate was increased more than two fold in the knockout growth cones compared with the wild type. These data suggest that both myosin IIA and IIB normally contribute to retrograde flow and the properties of the flow are strongly influenced by myosin IIB because of its location and abundance. However, in the absence of myosin IIB, myosin IIA takes over this function. The change in retrograde flow rate may reflect the difference in functional properties of these two myosins. Knockout growth cones also exhibited reduced stability of lamellipodia, possibly as a partial consequence of this increased retrograde flow rate. In addition, microtubules penetrated a shorter distance into filopodia, which suggests that the increase in flow rate may adversely affect the microtubule-dependent maturation of filopodia. Taken together these data support the idea that the forward advance of the growth cone is myosin II dependent and involves multiple myosin II isoforms.
This article has been cited by other articles:

|
 |

|
 |
 
N. Takizawa, R. Ikebe, M. Ikebe, and E. J. Luna
Supervillin slows cell spreading by facilitating myosin II activation at the cell periphery
J. Cell Sci.,
November 1, 2007;
120(21):
3792 - 3803.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. K. Sato, M. Takahashi, and M. Yazawa
Two Regions of the Tail Are Necessary for the Isoform-specific Functions of Nonmuscle Myosin IIB
Mol. Biol. Cell,
March 1, 2007;
18(3):
1009 - 1017.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Cai, N. Biais, G. Giannone, M. Tanase, G. Jiang, J. M. Hofman, C. H. Wiggins, P. Silberzan, A. Buguin, B. Ladoux, et al.
Nonmuscle Myosin IIA-Dependent Force Inhibits Cell Spreading and Drives F-Actin Flow
Biophys. J.,
November 15, 2006;
91(10):
3907 - 3920.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. D. Sousa, J. S. Berg, B. W. Robertson, R. B. Meeker, and R. E. Cheney
Myo10 in brain: developmental regulation, identification of a headless isoform and dynamics in neurons
J. Cell Sci.,
January 1, 2006;
119(1):
184 - 194.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Gehler, A. E. Shaw, P. D. Sarmiere, J. R. Bamburg, and P. C. Letourneau
Brain-Derived Neurotrophic Factor Regulation of Retinal Growth Cone Filopodial Dynamics Is Mediated through Actin Depolymerizing Factor/Cofilin
J. Neurosci.,
November 24, 2004;
24(47):
10741 - 10749.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Lee and J. E. Treisman
Excessive Myosin Activity in Mbs Mutants Causes Photoreceptor Movement Out of the Drosophila Eye Disc Epithelium
Mol. Biol. Cell,
July 1, 2004;
15(7):
3285 - 3295.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
X. Ma, S. Kawamoto, Y. Hara, and R. S. Adelstein
A Point Mutation in the Motor Domain of Nonmuscle Myosin II-B Impairs Migration of Distinct Groups of Neurons
Mol. Biol. Cell,
June 1, 2004;
15(6):
2568 - 2579.
[Abstract]
[Full Text]
[PDF]
|
 |
|
© The Company of Biologists Ltd 2003