title: Constructing modular and universal single molecule tension sensor using protein G to study mechano-sensitive receptors.
abstract: Recently a variety of molecular force sensors have been developed to study cellular forces acting through single mechano-sensitive receptors. A common strategy adopted is to attach ligand molecules on a surface through engineered molecular tethers which report cell-exerted tension on receptor-ligand bonds. This approach generally requires chemical conjugation of the ligand to the force reporting tether which can be time-consuming and labor-intensive. Moreover, ligand-tether conjugation can severely reduce the activity of protein ligands. To address this problem, we developed a Protein G (ProG)-based force sensor in which force-reporting tethers are conjugated to ProG instead of ligands. A recombinant ligand fused with IgG-Fc is conveniently assembled with the force sensor through ProG:Fc binding, therefore avoiding ligand conjugation and purification processes. Using this approach, we determined that molecular tension on E-cadherin is lower than dsDNA unzipping force (nominal value: 12 pN) during initial cadherin-mediated cell adhesion, followed by an escalation to forces higher than 43 pN (nominal value). This approach is highly modular and potentially universal as we demonstrate using two additional receptor-ligand interactions, P-selectin &PSGL-1 and Notch &DLL1.
authors.affiliation: Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Rahil
authors.affiliation: Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Chemistry, University of British Columbia Okanagan, Kelowna, BC, V1V1V7, Canada.
authors.forename: Isaac T S
authors.initials: IT
authors.lastname: Li
authors.affiliation: Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Mechanical Engineering and Energy Processes, Southern Illinois University, Carbondale, Illinois 62901, USA.
authors.forename: Farhan
authors.initials: F
authors.lastname: Chowdhury
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Leckband
authors.affiliation: Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Yann R
authors.initials: YR
authors.lastname: Chemla
authors.affiliation: Department of Physics, Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Howard Hughes Medical Institute, Baltimore, MD, 21218, USA.|Department of Biophysics &Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA.|Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Taekjip
authors.initials: T
authors.lastname: Ha
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D016466:CHO Cells; D015820:Cadherins / Q000502:physiology; D002448:Cell Adhesion; D003412:Cricetulus; D004247:DNA / Q000502:physiology; D006801:Humans; D008465:Mechanoreceptors / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D015820:Cadherins; D011994:Recombinant Proteins; D004247:DNA