Vinculin is an actin-binding protein thought to reinforce cell-cell and cell-matrix adhesions. However, how mechanical load affects the vinculin-F-actin bond is unclear. Using a single-molecule optical trap assay, we found that vinculin forms a force-dependent catch bond with F-actin through its tail domain, but with lifetimes that depend strongly on the direction of the applied force. Force toward the pointed (-) end of the actin filament resulted in a bond that was maximally stable at 8 piconewtons, with a mean lifetime (12 seconds) 10 times as long as the mean lifetime when force was applied toward the barbed (+) end. A computational model of lamellipodial actin dynamics suggests that the directionality of the vinculin-F-actin bond could establish long-range order in the actin cytoskeleton. The directional and force-stabilized binding of vinculin to F-actin may be a mechanism by which adhesion complexes maintain front-rear asymmetry in migrating cells.
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http://dx.doi.org/10.1126/science.aan2556 | DOI Listing |
J Mol Cell Cardiol
January 2025
Shu Chien-Gene Lay Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA; Institute of Engineering Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Sanford Consortium for Regenerative Medicine, La Jolla, CA 92093, USA. Electronic address:
Vinculin (VCL) is a key adapter protein located in force-bearing costamere complexes, which mechanically couples the sarcomere to the ECM. Heterozygous vinculin frameshift genetic variants can contribute to cardiomyopathy when external stress is applied, but the mechanosensitive pathways underpinning VCL haploinsufficiency remain elusive. Here, we show that in response to extracellular matrix stiffening, heterozygous loss of VCL disrupts force-mediated costamere protein recruitment, thereby impairing cardiomyocyte contractility and sarcomere organization.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Marine Biology, Charney School of Marine Sciences, University of Haifa, Haifa 3498838, Israel.
Biomineralization is the utilization of different minerals by a vast array of organisms to form hard tissues and shape them in various forms. Within this diversity, a common feature of all mineralized tissues is their high stiffness, implying that mechanosensing could be commonly used in biomineralization. Yet, the role of mechanosensing in biomineralization is far from clear.
View Article and Find Full Text PDFVinculin forms a catch bond with the cytoskeletal polymer actin, displaying an increased bond lifetime upon force application. Notably, this behavior depends on the direction of the applied force, which has significant implications for cellular mechanotransduction. In this study, we present a comprehensive molecular dynamics simulation study, employing enhanced sampling techniques to investigate the thermodynamic, kinetic, and mechanistic aspects of this phenomenon at physiologically relevant forces.
View Article and Find Full Text PDFMater Today Bio
August 2024
School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, 450001, PR China.
Uniaxial cyclic stretching plays a pivotal role in the fields of tissue engineering and regenerative medicine, influencing cell behaviors and functionality based on physical properties, including matrix morphology and mechanical stimuli. This study delves into the response of endothelial cells to uniaxial cyclic strain within the geometric constraints of micro-nano fibers. Various structural scaffold forms of poly(l-lactide--caprolactone) (PLCL), such as flat membranes, randomly oriented fiber membranes, and aligned fiber membranes, were fabricated through solvent casting and electrospinning methods.
View Article and Find Full Text PDFbioRxiv
March 2024
Department of Dermatology, Northwestern University, The Feinberg School of Medicine, Chicago, IL 60611.
Cadherins are transmembrane adhesion receptors. Cadherin ectodomains form adhesive 2D clusters through cooperative and interactions, whereas its intracellular region interacts with specific cytosolic proteins, termed catenins, to anchor the cadherin-catenin complex (CCC) to the actin cytoskeleton. How these two types of interactions are coordinated in the formation of specialized cell-cell adhesions, adherens junctions (AJ), remains unclear.
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