β1- and αv-class integrins cooperate to regulate myosin II during rigidity sensing of fibronectin-based microenvironments

Nat Cell Biol. 2013 Jun;15(6):625-36. doi: 10.1038/ncb2747. Epub 2013 May 26.

Abstract

How different integrins that bind to the same type of extracellular matrix protein mediate specific functions is unclear. We report the functional analysis of β1- and αv-class integrins expressed in pan-integrin-null fibroblasts seeded on fibronectin. Reconstitution with β1-class integrins promotes myosin-II-independent formation of small peripheral adhesions and cell protrusions, whereas expression of αv-class integrins induces the formation of large focal adhesions. Co-expression of both integrin classes leads to full myosin activation and traction-force development on stiff fibronectin-coated substrates, with αv-class integrins accumulating in adhesion areas exposed to high traction forces. Quantitative proteomics linked αv-class integrins to a GEF-H1-RhoA pathway coupled to the formin mDia1 but not myosin II, and α5β1 integrins to a RhoA-Rock-myosin II pathway. Our study assigns specific functions to distinct fibronectin-binding integrins, demonstrating that α5β1integrins accomplish force generation, whereas αv-class integrins mediate the structural adaptations to forces, which cooperatively enable cells to sense the rigidity of fibronectin-based microenvironments.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / metabolism
  • Cell Adhesion
  • Cell Line
  • Cell Movement
  • Cellular Microenvironment*
  • Extracellular Matrix / metabolism
  • Extracellular Matrix Proteins / metabolism
  • Fibroblasts
  • Fibronectins / metabolism*
  • Focal Adhesions / metabolism
  • Formins
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • Integrin alpha5beta1 / metabolism
  • Integrin alphaV / metabolism*
  • Integrin beta1 / metabolism*
  • Male
  • Mice
  • Mice, Transgenic
  • Myosin Type II / metabolism*
  • Protein Binding
  • Protein-Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism
  • RNA Interference
  • RNA, Small Interfering
  • Rho Guanine Nucleotide Exchange Factors
  • rho-Associated Kinases / metabolism
  • rhoA GTP-Binding Protein / metabolism

Substances

  • Arhgef2 protein, mouse
  • Carrier Proteins
  • Diap1 protein, mouse
  • Extracellular Matrix Proteins
  • Fibronectins
  • Formins
  • Guanine Nucleotide Exchange Factors
  • Integrin alpha5beta1
  • Integrin alphaV
  • Integrin beta1
  • Proto-Oncogene Proteins
  • RNA, Small Interfering
  • Rho Guanine Nucleotide Exchange Factors
  • integrin-linked kinase
  • Protein-Serine-Threonine Kinases
  • rho-Associated Kinases
  • Myosin Type II
  • rhoA GTP-Binding Protein