|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 113, Issue 17 3003-3012, Copyright © 2000 by Company of Biologists
JOURNAL ARTICLES |
PW Grabham, M Foley, A Umeojiako and DJ Goldberg
Department of Pharmacology and Center for Neurobiology and Behavior, Columbia University, New York, NY 10032, USA. pwg2@columbia.edu
The cycling of membrane receptors for substrate-bound proteins via their interaction with the actin cytoskeleton at the leading edge of growth cones and other motile cells is important for neurite outgrowth and cell migration. Receptor delivered to the leading edge binds to its ligand, which induces coupling of the receptor to a rearward flowing network of actin filaments. This coupling is thought to facilitate advance. We show here that a soluble growth factor stimulates this cycling. We have used single particle tracking to monitor the effects of nerve growth factor (NGF) on the movements of beta1 integrin in the plane of the plasma membrane of the filopodia of growth cones. Beta1 integrin was visualized by its binding of 0.2 microm beads coated with a monoclonal Ab directed against an extracellular epitope distant from the binding site for extracellular matrix ligands. The beads were observed by video microscopy. Beads coated with a low concentration of antibody, and therefore bound to unliganded receptor with little cross-linking, showed an increase in both diffusion and directed forward transport in response to NGF. Transport had a net velocity of 37 microm/minute and was characterized by brief periods of sustained forward excursions with a velocity of 75-150 microm/minute. There was a 2-fold increase in the number of beads accumulated at the tips of filopodia after 10 minutes, indicating that NGF enhanced the delivery of beta1 integrin to the periphery. Forward transport was dependent on an intact actin cytoskeleton and myosin ATPase, since treatment with cytochalasin D or the myosin ATPase inhibitor butanedione monoxime inhibited the transport but not the diffusion of receptors. NGF also greatly increased the steady rearward migration of beads coated with a high density of (&bgr;)1 integrin antibody, indicating that coupling of cross-linked receptor to the retrograde flow of actin is also enhanced. The rate of the retrograde flow of actin was unaffected by NGF. These studies show that a soluble factor can stimulate the coupling of a receptor for substrate-bound factor to two actomyosin-based transport mechanisms and thus facilitate the response of the growth cone to the substrate-bound factor by increasing cycling of the receptor at the periphery.
This article has been cited by other articles:
![]() |
T. Shimada, M. Toriyama, K. Uemura, H. Kamiguchi, T. Sugiura, N. Watanabe, and N. Inagaki Shootin1 interacts with actin retrograde flow and L1-CAM to promote axon outgrowth J. Cell Biol., October 20, 2008; 181(5): 817 - 829. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Falk, O. Thoumine, C. Dequidt, D. Choquet, and C. Faivre-Sarrailh NrCAM Coupling to the Cytoskeleton Depends on Multiple Protein Domains and Partitioning into Lipid Rafts Mol. Biol. Cell, October 1, 2004; 15(10): 4695 - 4709. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Serge, L. Fourgeaud, A. Hemar, and D. Choquet Active surface transport of metabotropic glutamate receptors through binding to microtubules and actin flow J. Cell Sci., December 15, 2003; 116(24): 5015 - 5022. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. DeMali and K. Burridge Coupling membrane protrusion and cell adhesion J. Cell Sci., June 15, 2003; 116(12): 2389 - 2397. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. C. Wildering, P. M. Hermann, and A. G. M. Bulloch Rapid Neuromodulatory Actions of Integrin Ligands J. Neurosci., April 1, 2002; 22(7): 2419 - 2426. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Kamiguchi and F. Yoshihara The Role of Endocytic L1 Trafficking in Polarized Adhesion and Migration of Nerve Growth Cones J. Neurosci., December 1, 2001; 21(23): 9194 - 9203. [Abstract] [Full Text] [PDF] |
||||