Abstract
Directional migration moves cells rapidly between points, whereas random migration allows cells to explore their local environments. We describe a Rac1 mechanism for determining whether cell patterns of migration are intrinsically random or directionally persistent. Rac activity promoted the formation of peripheral lamellae that mediated random migration. Decreasing Rac activity suppressed peripheral lamellae and switched the cell migration patterns of fibroblasts and epithelial cells from random to directionally persistent. In three-dimensional rather than traditional two-dimensional cell culture, cells had a lower level of Rac activity that was associated with rapid, directional migration. In contrast to the directed migration of chemotaxis, this intrinsic directional persistence of migration was not mediated by phosphatidylinositol 3'-kinase lipid signaling. Total Rac1 activity can therefore provide a regulatory switch between patterns of cell migration by a mechanism distinct from chemotaxis.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Cell Culture Techniques
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Cell Movement / physiology*
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Cell Surface Extensions / metabolism
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Cells, Cultured
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Epithelial Cells / cytology
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Epithelial Cells / metabolism
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Fibroblasts / cytology
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Fibroblasts / metabolism
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Fibronectins / metabolism
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Guanosine Triphosphate / metabolism
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Humans
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Integrins / genetics
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Integrins / metabolism
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Phosphatidylinositol 3-Kinases / metabolism
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Phosphoinositide-3 Kinase Inhibitors
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RNA, Small Interfering / genetics
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RNA, Small Interfering / metabolism
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Random Allocation
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Signal Transduction / physiology
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cdc42 GTP-Binding Protein / genetics
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cdc42 GTP-Binding Protein / metabolism
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rac GTP-Binding Proteins / genetics
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rac GTP-Binding Proteins / metabolism*
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rho GTP-Binding Proteins / genetics
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rho GTP-Binding Proteins / metabolism
Substances
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Fibronectins
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Integrins
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Phosphoinositide-3 Kinase Inhibitors
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RNA, Small Interfering
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Guanosine Triphosphate
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cdc42 GTP-Binding Protein
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rac GTP-Binding Proteins
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rho GTP-Binding Proteins