title: Integrins β1 and β3 exhibit distinct dynamic nanoscale organizations inside focal adhesions.
abstract: Integrins in focal adhesions (FAs) mediate adhesion and force transmission to extracellular matrices essential for cell motility, proliferation and differentiation. Different fibronectin-binding integrins, simultaneously present in FAs, perform distinct functions. Yet, how integrin dynamics control biochemical and biomechanical processes in FAs is still elusive. Using single-protein tracking and super-resolution imaging we revealed the dynamic nano-organizations of integrins and talin inside FAs. Integrins reside in FAs through free-diffusion and immobilization cycles. Integrin activation promotes immobilization, stabilized in FAs by simultaneous connection to fibronectin and actin-binding proteins. Talin is recruited in FAs directly from the cytosol without membrane free-diffusion, restricting integrin immobilization to FAs. Immobilized β3-integrins are enriched and stationary within FAs, whereas immobilized β1-integrins are less enriched and exhibit rearward movements. Talin is enriched and mainly stationary, but also exhibited rearward movements in FAs, consistent with stable connections with both β-integrins. Thus, differential transmission of actin motion to fibronectin occurs through specific integrins within FAs.
authors.affiliation: Interdisciplinary Institute for Neuroscience, University of Bordeaux, UMR 5297, F-33000 Bordeaux, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Rossier
authors.forename: Vivien
authors.initials: V
authors.lastname: Octeau
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Sibarita
authors.forename: Cécile
authors.initials: C
authors.lastname: Leduc
authors.forename: Béatrice
authors.initials: B
authors.lastname: Tessier
authors.forename: Deepak
authors.initials: D
authors.lastname: Nair
authors.forename: Volker
authors.initials: V
authors.lastname: Gatterdam
authors.forename: Olivier
authors.initials: O
authors.lastname: Destaing
authors.forename: Corinne
authors.initials: C
authors.lastname: Albigès-Rizo
authors.forename: Robert
authors.initials: R
authors.lastname: Tampé
authors.forename: Laurent
authors.initials: L
authors.lastname: Cognet
authors.forename: Daniel
authors.initials: D
authors.lastname: Choquet
authors.forename: Brahim
authors.initials: B
authors.lastname: Lounis
authors.forename: Grégory
authors.initials: G
authors.lastname: Giannone
mesh_terms: D000818:Animals; D005353:Fibronectins / Q000378:metabolism; D022001:Focal Adhesions / Q000378:metabolism*; D019012:Integrin beta1 / Q000378:metabolism*; D039661:Integrin beta3 / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D011485:Protein Binding; D016608:Talin / Q000378:metabolism
chemical_list: D005353:Fibronectins; D019012:Integrin beta1; D039661:Integrin beta3; D008840:Microfilament Proteins; D016608:Talin; C496077:Tln1 protein, mouse