title: The LIM domain of zyxin is sufficient for force-induced accumulation of zyxin during cell migration.
abstract: Cellular responses to mechanical perturbation are vital to cell physiology. In particular, migrating cells have been shown to sense substrate stiffness and alter cell morphology and speed. Zyxin is a focal adhesion protein that responds to external mechanical forces; however, the mechanisms of zyxin recruitment at force-bearing sites are unknown. Using force-sensing microfabricated substrates, we simultaneously measured traction force and zyxin recruitment at force-bearing sites. GFP-tagged zyxin accumulates at force-bearing sites at the leading edge, but not at the trailing edge, of migrating epithelial cells. Zyxin recruitment at force-bearing sites depends on Rho-kinase and myosin II activation, suggesting that zyxin responds not only to the externally applied force, as previously shown, but also to the internally generated actin-myosin force. Zyxin in turn recruits vasodilator-stimulated phosphoprotein, a regulator of actin assembly, to force-bearing sites. To dissect the domains of zyxin that are essential for this unique force-dependent accumulation, we generated two zyxin truncation mutants: one lacking the LIM domain (ΔLIM) and one containing only the LIM domain with all three LIM motifs (LIM). GFP-tagged ΔLIM does not localize to the force-bearing sites, but GFP-tagged zyxin LIM-domain is sufficient for the recruitment to and dynamics at force-bearing focal adhesions. Furthermore, one or two LIM motifs are not sufficient for force-dependent accumulation, suggesting that all three LIM motifs are required. Therefore, the LIM domain of zyxin recruits zyxin to force-bearing sites at the leading edge of migrating cells.
authors: Department of Biomedical Engineering, University of California, Davis, California, USA.
authors: Arisa
authors: A
authors: Uemura
authors: Thuc-Nghi
authors: TN
authors: Nguyen
authors: Amanda N
authors: AN
authors: Steele
authors: Soichiro
authors: S
authors: Yamada
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D001696:Biomechanical Phenomena; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement; D004285:Dogs; D006801:Humans; D055595:Mechanical Phenomena; D008840:Microfilament Proteins / Q000378:metabolism; D024462:Myosin Type II / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D017434:Protein Structure, Tertiary; D060589:Zyxin / Q000737:chemistry* / Q000378:metabolism*; D054460:rho-Associated Kinases / Q000378:metabolism; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D060589:Zyxin; D000098662:Vasodilator-Stimulated Phosphoprotein; D054460:rho-Associated Kinases; D024462:Myosin Type II