Actin and microtubules in neurite initiation: Are MAPs the missing link?
Article first published online: 29 OCT 2003
Copyright © 2003 Wiley Periodicals, Inc.
Journal of Neurobiology
Special Issue: Functions of the Cytoskeleton in Neural Development
Volume 58, Issue 1, pages 18–33, January 2004
How to Cite
Dehmelt, L. and Halpain, S. (2004), Actin and microtubules in neurite initiation: Are MAPs the missing link?. J. Neurobiol., 58: 18–33. doi: 10.1002/neu.10284
- Issue published online: 29 OCT 2003
- Article first published online: 29 OCT 2003
- Manuscript Accepted: 28 APR 2003
- Manuscript Received: 27 MAR 2003
- NIH. Grant Number: MH50861
- microtubule-associated proteins;
- growth cones
During neurite initiation microtubules align to form a tight bundle and actin filaments reorganize to produce a growth cone. The mechanisms that underlie these highly coordinated cytoskeletal rearrangements are not yet fully understood. Recently, various levels of coordination between the actin- and microtubule-based cytoskeletons have been observed during cellular migration and morphogenesis, processes that share some similarities to neurite initiation. Direct, physical association between both cytoskeletons has been suggested, because microtubules often preferentially grow along actin bundles and transiently target actin-rich adhesion complexes. We propose that such physical association might be involved in force-based interactions and spatial organization of the two networks during neurite initiation as well. In addition, many signaling cascades that affect actin filaments are also involved in the regulation of microtubule dynamics, and vice versa. Although several candidates for mediating these effects have been identified in non-neuronal cells, the general mechanism is still poorly understood. In neurons certain plakins and neuron-specific microtubule associated proteins (MAPs), like MAP1B and MAP2, which can bind to both microtubules and F-actin, are promising candidates to play key roles in the specific cytoskeletal rearrangements controlling the transition from an undifferentiated state to neurite-bearing morphology. Here we review the effects of MAPs on microtubules and actin, as well as the coordination of both cytoskeletons during neurite initiation. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 18–33, 2004