1. Myosin-IXA regulates collective epithelial cell migration by targeting RhoGAP activity to cell-cell junctions.
- Author
-
Omelchenko T and Hall A
- Subjects
- Cell Adhesion, Cell Differentiation, Cell Line, Fluorescence Resonance Energy Transfer, Humans, Microscopy, Phase-Contrast, Myosins genetics, RNA, Small Interfering genetics, cdc42 GTP-Binding Protein metabolism, rhoA GTP-Binding Protein metabolism, rhoB GTP-Binding Protein metabolism, Actin Cytoskeleton metabolism, Adherens Junctions metabolism, Cell Movement, Epithelial Cells metabolism, Myosins chemistry, Myosins metabolism
- Abstract
Background: Epithelial tissues undergo extensive collective movements during morphogenesis, repair, and renewal. Collective epithelial cell migration requires the intercellular coordination of cell-cell adhesions and the establishment of anterior-posterior polarity, while maintaining apical-basal polarity, but how this is achieved at the molecular level is not well understood., Results: Using an RNA interference-based screen to identify Rho family GTPase regulators required for the collective migration of human bronchial epithelial cells, we identified myosin-IXA (gene name: Myo9a). Depletion of myosin-IXA, a RhoGAP and actin motor protein, in collectively migrating cells led to altered organization of the actin cytoskeleton and tension-dependent disruption of cell-cell adhesions, followed by an inability to form new adhesions resulting in cell scattering. Closer examination revealed that myosin-IXA is required during the formation of junction-associated actin bundles soon after cell-cell contact. Structure-function analysis of myosin-IXA revealed that the motor domain is necessary and sufficient for binding to actin filaments, whereas expression of the RhoGAP domain partially rescued the cell scattering phenotype induced by myosin-IXA depletion. Finally, a fluorescence resonance energy transfer biosensor revealed a significant increase in Rho activity at nascent cell-cell contacts in myosin-IXA depleted cells compared to controls., Conclusion: We propose that myosin-IXA locally regulates Rho and the assembly of thin actin bundles associated with nascent cell-cell adhesions and that this is required to sustain the collective migration of epithelial cells., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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