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Mechanical signals regulate functions of mechanosensitive proteins by inducing structural changes that are determinant for force-dependent interactions. Talin is a focal adhesion protein that is known to extend under mechanical load, and it has been shown to unfold via intermediate states. Here, we compared different nonequilibrium molecular dynamics (MD) simulations to study unfolding of the talin rod. We combined boxed MD (BXD), steered MD, and umbrella sampling (US) techniques and provide free energy profiles for unfolding of talin rod subdomains. We conducted BXD, steered MD, and US simulations at different detail levels and demonstrate how these different techniques can be used to study protein unfolding under tension. Unfolding free energy profiles determined by BXD suggest that the intermediate states in talin rod subdomains are stabilized by force during unfolding, and US confirmed these results.
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http://dx.doi.org/10.1016/j.bpj.2020.07.030 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD 20892.
Focal adhesions (FAs) are large intracellular macromolecular assemblies that play a critical role in cell polarization and migration. Talin serves as a direct connection between integrin receptor and actomyosin cytoskeleton within FAs. Talin contains three actin-binding sites (ABS1-3) that engage discreetly during the development of FAs, thus acting as a critical player in FA initiation and maturation.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Cell Biology, Yale School of Medicine, USA.
Force-induced changes in protein structure and function mediate cellular responses to mechanical stresses. Existing methods to study protein conformation under mechanical force are incompatible with biochemical and structural analysis. Taking advantage of DNA nanotechnology, including the well-defined geometry of DNA origami and programmable mechanics of DNA hairpins, we built a nanodevice to apply controlled forces to proteins.
View Article and Find Full Text PDFACS Nano
October 2024
Yale Cardiovascular Research Center, Department of Internal Medicine (Cardiology), Yale University School of Medicine, New Haven, Connecticut 06511, United States.
Cellular mechanotransduction, a process central to cell biology, embryogenesis, adult physiology, and multiple diseases, is thought to be mediated by force-driven changes in protein conformation that control protein function. However, methods to study proteins under defined mechanical loads on a biochemical scale are lacking. We report the development of a DNA-based device in which the transition between single- and double-stranded DNA applies tension to an attached protein.
View Article and Find Full Text PDFCell Rep
September 2024
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Nanobiology Institute, Yale University, West Haven, CT 06516, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA. Electronic address:
Mechanical forces are transmitted from the actin cytoskeleton to the membrane during clathrin-mediated endocytosis (CME) in the fission yeast Schizosaccharomyces pombe. End4p directly transmits force in CME by binding to both the membrane (through the AP180 N-terminal homology [ANTH] domain) and F-actin (through the talin-HIP1/R/Sla2p actin-tethering C-terminal homology [THATCH] domain). We show that 7 pN force is required for stable binding between THATCH and F-actin.
View Article and Find Full Text PDFSci Adv
August 2024
Yale Cardiovascular Research Center, Cardiovascular Medicine, Department of Internal Medicine, Yale School of Medicine, Yale University, New Haven, CT 06511, USA.
Tissue mechanical properties are determined mainly by the extracellular matrix (ECM) and actively maintained by resident cells. Despite its broad importance to biology and medicine, tissue mechanical homeostasis remains poorly understood. To explore cell-mediated control of tissue stiffness, we developed mutations in the mechanosensitive protein talin 1 to alter cellular sensing of ECM.
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