title: Kindlin-3 Is Essential for the Resting α4β1 Integrin-mediated Firm Cell Adhesion under Shear Flow Conditions.
abstract: Integrin-mediated rolling and firm cell adhesion are two critical steps in leukocyte trafficking. Integrin α4β1 mediates a mixture of rolling and firm cell adhesion on vascular cell adhesion molecule-1 (VCAM-1) when in its resting state but only supports firm cell adhesion upon activation. The transition from rolling to firm cell adhesion is controlled by integrin activation. Kindlin-3 has been shown to bind to integrin β tails and trigger integrin activation via inside-out signaling. However, the role of kindlin-3 in regulating resting α4β1-mediated cell adhesion is not well characterized. Herein we demonstrate that kindlin-3 was required for the resting α4β1-mediated firm cell adhesion but not rolling adhesion. Knockdown of kindlin-3 significantly decreased the binding of kindlin-3 to β1 and down-regulated the binding affinity of the resting α4β1 to soluble VCAM-1. Notably, it converted the resting α4β1-mediated firm cell adhesion to rolling adhesion on VCAM-1 substrates, increased cell rolling velocity, and impaired the stability of cell adhesion. By contrast, firm cell adhesion mediated by Mn(2+)-activated α4β1 was barely affected by knockdown of kindlin-3. Structurally, lack of kindlin-3 led to a more bent conformation of the resting α4β1. Thus, kindlin-3 plays an important role in maintaining a proper conformation of the resting α4β1 to mediate both rolling and firm cell adhesion. Defective kindlin-3 binding to the resting α4β1 leads to a transition from firm to rolling cell adhesion on VCAM-1, implying its potential role in regulating the transition between integrin-mediated rolling and firm cell adhesion.
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: Ling
authors.initials: L
authors.lastname: Lu
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: ChangDong
authors.initials: C
authors.lastname: Lin
authors.affiliation: The Second Affiliated Hospital of Soochow University, Suzhou 215004, China.
authors.forename: ZhanJun
authors.initials: Z
authors.lastname: Yan
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: YouHua
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: ShiHui
authors.initials: S
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: JunLei
authors.initials: J
authors.lastname: Wang
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and.
authors.forename: Cui
authors.initials: C
authors.lastname: Liu
authors.affiliation: From the State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China and jfchen@sibcb.ac.cn.
authors.forename: JianFeng
authors.initials: J
authors.lastname: Chen
mesh_terms: D002448:Cell Adhesion / Q000502:physiology; D006801:Humans; D039041:Integrin alpha4beta1 / Q000235:genetics / Q000378:metabolism*; D020014:K562 Cells; D008345:Manganese / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D033081:Shear Strength; D015398:Signal Transduction / Q000502:physiology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism
chemical_list: C477322:FERMT3 protein, human; D039041:Integrin alpha4beta1; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D019010:Vascular Cell Adhesion Molecule-1; D008345:Manganese
keywords: cell adhesion; conformation; conformational change; firm cell adhesion; integrin; integrin α4β1; kindlin; kindlin-3; resting state; shear stress