title: Myosin II activity dependent and independent vinculin recruitment to the sites of E-cadherin-mediated cell-cell adhesion.
abstract: BACKGROUND
  Maintaining proper adhesion between neighboring cells depends on the ability of cells to mechanically respond to tension at cell-cell junctions through the actin cytoskeleton. Thus, identifying the molecules involved in responding to cell tension would provide insight into the maintenance, regulation, and breakdown of cell-cell junctions during various biological processes. Vinculin, an actin-binding protein that associates with the cadherin complex, is recruited to cell-cell contacts under increased tension in a myosin II-dependent manner. However, the precise role of vinculin at force-bearing cell-cell junctions and how myosin II activity alters the recruitment of vinculin at quiescent cell-cell contacts have not been demonstrated.
  
  
  RESULTS
  We generated vinculin knockdown cells using shRNA specific to vinculin and MDCK epithelial cells. These vinculin-deficient MDCK cells form smaller cell clusters in a suspension than wild-type cells. In wound healing assays, GFP-vinculin accumulated at cell-cell junctions along the wound edge while vinculin-deficient cells displayed a slower wound closure rate compared to vinculin-expressing cells. In the presence of blebbistatin (myosin II inhibitor), vinculin localization at quiescent cell-cell contacts was unaffected while in the presence of jasplakinolide (F-actin stabilizer), vinculin recruitment increased in mature MDCK cell monolayers.
  
  
  CONCLUSIONS
  These results demonstrate that vinculin plays an active role at adherens junctions under increased tension at cell-cell contacts where vinculin recruitment occurs in a myosin II activity-dependent manner, whereas vinculin recruitment to the quiescent cell-cell junctions depends on F-actin stabilization.
authors: Department of Biomedical Engineering, University of California, Davis Davis, CA 95616, USA.
authors: Grant M
authors: GM
authors: Sumida
authors: Tyler M
authors: TM
authors: Tomita
authors: Wenting
authors: W
authors: Shih
authors: Soichiro
authors: S
authors: Yamada
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism; D047630:Depsipeptides / Q000494:pharmacology; D004285:Dogs; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D024462:Myosin Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D016596:Vinculin / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000199:Actins; D000970:Antineoplastic Agents; D015820:Cadherins; D047630:Depsipeptides; D006576:Heterocyclic Compounds, 4 or More Rings; D034741:RNA, Small Interfering; C057531:jasplakinolide; D016596:Vinculin; C472645:blebbistatin; D024462:Myosin Type II