title: A Structural Model for Vinculin Insertion into PIP2-Containing Membranes and the Effect of Insertion on Vinculin Activation and Localization.
abstract: Vinculin, a scaffolding protein that localizes to focal adhesions (FAs) and adherens junctions, links the actin cytoskeleton to the adhesive super-structure. While vinculin binds to a number of cytoskeletal proteins, it can also associate with phosphatidylinositol 4,5-bisphosphate (PIP2) to drive membrane association. To generate a structural model for PIP2-dependent interaction of vinculin with the lipid bilayer, we conducted lipid-association, nuclear magnetic resonance, and computational modeling experiments. We find that two basic patches on the vinculin tail drive membrane association: the basic collar specifically recognizes PIP2, while the basic ladder drives association with the lipid bilayer. Vinculin mutants with defects in PIP2-dependent liposome association were then expressed in vinculin knockout murine embryonic fibroblasts. Results from these analyses indicate that PIP2binding is not required for localization of vinculin to FAs or FA strengthening, but is required for vinculin activation and turnover at FAs to promote its association with the force transduction FA nanodomain.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Thompson
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Srinivas
authors.initials: S
authors.lastname: Ramachandran
authors.affiliation: Cell Biology and Physiology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Lindsay B
authors.initials: LB
authors.lastname: Case
authors.affiliation: Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Caitlin E
authors.initials: CE
authors.lastname: Tolbert
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Arpit
authors.initials: A
authors.lastname: Tandon
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Mihir
authors.initials: M
authors.lastname: Pershad
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Nikolay V
authors.initials: NV
authors.lastname: Dokholyan
authors.affiliation: Cell Biology and Physiology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Clare M
authors.initials: CM
authors.lastname: Waterman
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address: campbesl@med.unc.edu.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Campbell
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D000199:Actins / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure; D022001:Focal Adhesions / Q000378:metabolism* / Q000648:ultrastructure; D015870:Gene Expression; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D040542:Mechanotransduction, Cellular; D051379:Mice; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D054730:Protein Interaction Domains and Motifs; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013816:Thermodynamics; D016596:Vinculin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D008051:Lipid Bilayers; D019269:Phosphatidylinositol 4,5-Diphosphate; D011994:Recombinant Proteins; D016596:Vinculin
keywords: PIP2; focal adhesion; iPALM; lipid bilayer; molecular dynamics; nuclear magnetic resonance; vinculin