title: Force-dependent conformational switch of α-catenin controls vinculin binding.
abstract: Force sensing at cadherin-mediated adhesions is critical for their proper function. α-Catenin, which links cadherins to actomyosin, has a crucial role in this mechanosensing process. It has been hypothesized that force promotes vinculin binding, although this has never been demonstrated. X-ray structure further suggests that α-catenin adopts a stable auto-inhibitory conformation that makes the vinculin-binding site inaccessible. Here, by stretching single α-catenin molecules using magnetic tweezers, we show that the subdomains MI vinculin-binding domain (VBD) to MIII unfold in three characteristic steps: a reversible step at ~5 pN and two non-equilibrium steps at 10-15 pN. 5 pN unfolding forces trigger vinculin binding to the MI domain in a 1:1 ratio with nanomolar affinity, preventing MI domain refolding after force is released. Our findings demonstrate that physiologically relevant forces reversibly unfurl α-catenin, activating vinculin binding, which then stabilizes α-catenin in its open conformation, transforming force into a sustainable biochemical signal.
authors: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2].
authors: Mingxi
authors: M
authors: Yao
authors: 1] Department of Physics, National University of Singapore, Singapore 117542, Singapore [2] College of Physics, Chongqing University, No. 55 Daxuecheng South Road, Chongqing 401331, China [3].
authors: Wu
authors: W
authors: Qiu
authors: 1] Department of Physics, National University of Singapore, Singapore 117542, Singapore [2] College of Physics, Chongqing University, No. 55 Daxuecheng South Road, Chongqing 401331, China.
authors: Ruchuan
authors: R
authors: Liu
authors: Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore.
authors: Artem K
authors: AK
authors: Efremov
authors: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] Singapore-MIT Alliance for Research and Technology, National University of Singapore, Singapore 117543, Singapore.
authors: Peiwen
authors: P
authors: Cong
authors: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Paris 75013, France.
authors: Rima
authors: R
authors: Seddiki
authors: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Paris 75013, France.
authors: Manon
authors: M
authors: Payre
authors: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] Department of Bioengineering, National University of Singapore, Singapore 117542, Singapore.
authors: Chwee Teck
authors: CT
authors: Lim
authors: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Paris 75013, France.
authors: Benoit
authors: B
authors: Ladoux
authors: Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Paris 75013, France.
authors: René-Marc
authors: RM
authors: Mège
authors: 1] Mechanobiology Institute, National University of Singapore, Singapore 117411, Singapore [2] College of Physics, Chongqing University, No. 55 Daxuecheng South Road, Chongqing 401331, China [3] Department of Bioengineering, National University of Singapore, Singapore 117542, Singapore [4] Centre for Bioimaging Sciences, National University of Singapore, Singapore 117546, Singapore.
authors: Jie
authors: J
authors: Yan
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D005786:Gene Expression Regulation; D060526:Magnetic Fields; D040542:Mechanotransduction, Cellular; D051379:Mice; D052898:Optical Tweezers; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013314:Stress, Mechanical; D016596:Vinculin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051178:alpha Catenin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D011993:Recombinant Fusion Proteins; D051178:alpha Catenin; D016596:Vinculin