Humphries, J. D. et al. Vinculin controls focal adhesion formation by direct interactions with talin and actin. J. Cell Biol. 179, 1043-1057

Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester M13 9PT, England, UK.
The Journal of Cell Biology (Impact Factor: 9.83). 01/2008; 179(5):1043-57. DOI: 10.1083/jcb.200703036
Source: PubMed


Focal adhesions (FAs) regulate cell migration. Vinculin, with its many potential binding partners, can interconnect signals in FAs. Despite the well-characterized structure of vinculin, the molecular mechanisms underlying its action have remained unclear. Here, using vinculin mutants, we separate the vinculin head and tail regions into distinct functional domains. We show that the vinculin head regulates integrin dynamics and clustering and the tail regulates the link to the mechanotransduction force machinery. The expression of vinculin constructs with unmasked binding sites in the head and tail regions induces dramatic FA growth, which is mediated by their direct interaction with talin. This interaction leads to clustering of activated integrin and an increase in integrin residency time in FAs. Surprisingly, paxillin recruitment, induced by active vinculin constructs, occurs independently of its potential binding site in the vinculin tail. The vinculin tail, however, is responsible for the functional link of FAs to the actin cytoskeleton. We propose a new model that explains how vinculin orchestrates FAs.

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    • "Paxillin and vinculin are multi-domain adapter proteins that are key regulators of focal-adhesion formation and cell adhesion [24] [25]. To elucidate in greater detail the mechanism by which NAC restores cell adhesion upon exposure to oxidative stress, "
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    • "constitutively open conformation (Marg et al., 2010). Constitutively active T12 mutants also displayed slower exchange dynamics in focal adhesions but a similarly increased immobile fraction compared to phospho-mimicking vinculin (Cohen et al., 2006; Humphries et al., 2007). Interestingly, the force transmission in T12 mutants, in phospho-mimicking vinculin mutants and in rescue cells was similar, suggesting that the vinculin present in the focal adhesions of wild-type cells is mostly in an open, active conformation, which is in agreement with data from FRET-based experiments (Chen et al., 2005). "
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    • "Moreover, experimental evidence has been presented in support of talin binding to the FAT domain of FAK via the talin-innate FERM domain, independently of FAK-paxillin binding (Lawson et al. 2012). Vinculin is essential for focal adhesions, since, on the one hand, vinculin interconnection with α-actinin yields the bonding of the β1- integrin with the filamentous-actin cytoskeleton and, on the other hand, the vinculin-talin interaction leads to membrane accumulation of activated β1-integrins concomitant with emerging focal adhesion growth (Humphries et al. 2007; Ziegler et al. 2008). Observations from mouse embryonic fibroblasts derived from vinculin knock-out animals reveal smaller focal adhesions, diminished adhesion on various ECM proteins, but faster migration as knock-out consequences (Xu et al. 1998), thereby suggesting that vinculin is important for the reinforcement of environmental cell attachment (Carisey and Ballestrem 2011). "
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