Elife
Departments of Structural Biology and Molecular & Cellular Physiology, Stanford University School of Medicine, Stanford, United States.
Published: September 2020
Cell-cell and cell-matrix junctions transmit mechanical forces during tissue morphogenesis and homeostasis. α-Catenin links cell-cell adhesion complexes to the actin cytoskeleton, and mechanical load strengthens its binding to F-actin in a direction-sensitive manner. Specifically, optical trap experiments revealed that force promotes a transition between weak and strong actin-bound states. Here, we describe the cryo-electron microscopy structure of the F-actin-bound αE-catenin actin-binding domain, which in solution forms a five-helix bundle. In the actin-bound structure, the first helix of the bundle dissociates and the remaining four helices and connecting loops rearrange to form the interface with actin. Deletion of the first helix produces strong actin binding in the absence of force, suggesting that the actin-bound structure corresponds to the strong state. Our analysis explains how mechanical force applied to αE-catenin or its homolog vinculin favors the strongly bound state, and the dependence of catch bond strength on the direction of applied force.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7588230 | PMC |
http://dx.doi.org/10.7554/eLife.60878 | DOI Listing |
RSC Chem Biol
January 2025
Department of Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine Kamigyo-ku 465 Kajii-cho Kyoto 602-8566 Japan
A multiomic study of the structural characteristics of type A and B influenza viruses by means of highly spectrally resolved Raman spectroscopy is presented. Three virus strains, A H1N1, A H3N2, and B98, were selected because of their known structural variety and because they have co-circulated with variable relative prevalence within the human population since the re-emergence of the H1N1 subtype in 1977. Raman signatures of protein side chains tyrosine, tryptophan, and histidine revealed unequivocal and consistent differences for pH characteristics at the virion surface, while different conformations of two C-S bond configurations in and methionine rotamers provided distinct low-wavenumber fingerprints for different virus lineages/subtypes.
View Article and Find Full Text PDFImmunol Rev
January 2025
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
αβT cells protect vertebrates against many diseases, optimizing surveillance using mechanical force to distinguish between pathophysiologic cellular alterations and normal self-constituents. The multi-subunit αβT-cell receptor (TCR) operates outside of thermal equilibrium, harvesting energy via physical forces generated by T-cell motility and actin-myosin machinery. When a peptide-bound major histocompatibility complex molecule (pMHC) on an antigen presenting cell is ligated, the αβTCR on the T cell leverages force to form a catch bond, prolonging bond lifetime, and enhancing antigen discrimination.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Biology, University of Oxford, Mansfield Road, Oxford, OX1 3SZ, UK.
Long-distance migrants must optimise their timing of breeding to capitalise on resources at both breeding and over-wintering sites. In species with protracted breeding seasons, departing earlier on migration might be advantageous, but is constrained by the ongoing breeding attempt. Here we investigated how breeding timing affects migratory strategies in the Manx shearwater (Puffinus puffinus), a trans-hemispheric migratory seabird with large temporal variation in the onset of breeding.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Biochemistry, University of Washington, Seattle, WA.
A critical step in infections is the attachment of many microorganisms to host cells using lectins that bind surface glycans, making lectins promising antimicrobial targets. Upon binding mannosylated glycans, FimH, the most studied lectin adhesin of type 1 fimbriae in , undergoes an allosteric transition from an inactive to an active conformation that can act as a catch-bond. Monoclonal antibodies that alter FimH glycan binding in various ways are available, but the mechanisms of these antibodies remain unclear.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania, USA.
Bidirectional cargo transport by kinesin and dynein is essential for cell viability and defects are linked to neurodegenerative diseases. The competition between motors is described as a tug-of-war, and computational modeling suggests that the load-dependent off-rate is the strongest determinant of which motor 'wins'. Optical tweezer experiments find that the load-dependent detachment sensitivity of transport kinesins is kinesin-3 > kinesin-2 > kinesin-1.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.