4dj9
Human vinculin head domain Vh1 (residues 1-258) in complex with the talin vinculin binding site 50 (VBS50, residues 2078-2099)Human vinculin head domain Vh1 (residues 1-258) in complex with the talin vinculin binding site 50 (VBS50, residues 2078-2099)
Structural highlights
Disease[VINC_HUMAN] Defects in VCL are the cause of cardiomyopathy dilated type 1W (CMD1W) [MIM:611407]. Dilated cardiomyopathy is a disorder characterized by ventricular dilation and impaired systolic function, resulting in congestive heart failure and arrhythmia. Patients are at risk of premature death.[1] [2] Defects in VCL are the cause of familial hypertrophic cardiomyopathy type 15 (CMH15) [MIM:613255]. It is a hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death.[3] Function[VINC_HUMAN] Actin filament (F-actin)-binding protein involved in cell-matrix adhesion and cell-cell adhesion. Regulates cell-surface E-cadherin expression and potentiates mechanosensing by the E-cadherin complex. May also play important roles in cell morphology and locomotion.[4] [TLN1_HUMAN] Probably involved in connections of major cytoskeletal structures to the plasma membrane. High molecular weight cytoskeletal protein concentrated at regions of cell-substratum contact and, in lymphocytes, at cell-cell contacts (By similarity). Publication Abstract from PubMedThe cytoskeletal protein talin activates integrin receptors by binding of its FERM domain to the cytoplasmic tail of beta-integrin. Talin also couples integrins to the actin cytoskeleton, largely by binding to and activating the cytoskeletal protein vinculin, which binds to F-actin through the agency of its five-helix bundle tail (Vt) domain. Talin activates vinculin by means of buried amphipathic alpha-helices coined vinculin binding sites (VBSs) that reside within numerous four- and five-helix bundle domains that comprise the central talin rod, which are released from their buried locales by means of mechanical tension on the integrin:talin complex. In turn, these VBSs bind to the N-terminal seven-helix bundle (Vh1) domain of vinculin, creating an entirely new helix bundle that severs its head-tail interactions. Interestingly, talin harbors a second integrin binding site coined IBS2 that consists of two five-helix bundle domains that also contain a VBS (VBS50). Here we report the crystal structure of VBS50 in complex with vinculin at 2.3 A resolution and show that intramolecular interactions of VBS50 within IBS2 are much more extensive versus its interactions with vinculin. Indeed, the IBS2-vinculin interaction only occurs at physiological temperature and the affinity of VBS50 for vinculin is about 30 times less than other VBSs. The data support a model where integrin binding destabilizes IBS2 to allow it to bind to vinculin. Crystal structure of vinculin in complex with vinculin binding site 50 (VBS50), the integrin binding site 2 (IBS2) of talin.,Yogesha SD, Rangarajan ES, Vonrhein C, Bricogne G, Izard T Protein Sci. 2012 Feb 14. doi: 10.1002/pro.2041. PMID:22334306[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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