Microtubule release from the centrosome in migrating cells.
In migrating cells, force production relies essentially on a polarized actomyosin system, whereas the spatial regulation of actomyosin contraction and substrate contact turnover involves a complex cooperation between the microtubule (MT) and the actin filament networks (Goode, B.L., D.G. Drubin, and G. Barnes. 2000. Curr. Opin. Cell Biol., 12:63-71). Targeting and capture of MT plus ends at the cell periphery has been described, but whether or not the minus ends of these MTs are anchored at the centrosome is not known. Here, we show that release of short MTs from the centrosome is frequent in migrating cells and that their transport toward the cell periphery is blocked when dynein activity is impaired. We further show that MT release, but not MT nucleation or polymerization dynamics, is abolished by overexpression of the centrosomal MT-anchoring protein ninein. In addition, a dramatic inhibition of cell migration was observed; but, contrary to cells treated by drugs inhibiting MT dynamics, polarized membrane ruffling activity was not affected in ninein overexpressing cells. We thus propose that the balance between MT minus-end capture and release from the centrosome is critical for efficient cell migration.
Abal
Miguel
M
Institut Curie/UMR 144 du Centre National de la Recherche Scientifique, 75248 Paris, France.
Piel
Matthieu
M
Bouckson-Castaing
Veronique
V
Mogensen
Mette
M
Sibarita
Jean-Baptiste
JB
Bornens
Michel
M
D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D018385:Centrosome / Q000378:metabolism / Q000502:physiology*; D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; D004398:Dyneins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000502:physiology; D019204:GTP-Binding Proteins / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007202:Indicators and Reagents; D007700:Kinetics; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D018715:Microscopy, Video / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism / Q000502:physiology*; D015739:Nocodazole / Q000494:pharmacology; D009687:Nuclear Proteins; D012867:Skin / Q000166:cytology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D003598:Cytoskeletal Proteins; D000072159:Dynactin Complex; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D008869:Microtubule-Associated Proteins; C512806:NIN protein, human; C099035:Nin protein, mouse; D009687:Nuclear Proteins; D049452:Green Fluorescent Proteins; D019204:GTP-Binding Proteins; D004398:Dyneins; D015739:Nocodazole