title: Polymerization of type I and III collagens is dependent on fibronectin and enhanced by integrins alpha 11beta 1 and alpha 2beta 1.
abstract: Polymerization of the ECM proteins fibronectin and laminin has been shown to take place in close vicinity to the cell surface and be facilitated by beta(1) integrins (Lohikangas, L., Gullberg, D., and Johansson, S. (2001) Exp. Cell Res. 265, 135-144 and Wennerberg, K., Lohikangas, L., Gullberg, D., Pfaff, M., Johansson, S., and Fassler, R. (1996) J. Cell Biol. 132, 227-238). We have studied the role of collagen receptors, integrins alpha(11)beta(1) and alpha(2)beta(1), and fibronectin in collagen polymerization using fibronectin-deficient mouse embryonic fibroblast cell lines. In contrast to the earlier belief that collagen polymerization occurs via self-assembly of collagen molecules we show that a preformed fibronectin matrix is essential for collagen network formation and that collagen-binding integrins strongly enhance this process. Thus, collagen deposition is regulated by the cells, both indirectly through integrin alpha(5)beta(1)-dependent polymerization of fibronectin and directly through collagen-binding integrins.
authors.affiliation: Institute of Medical Biochemistry and Microbiology, 75123 Uppsala, Sweden. teet.velling@imbim.uu.se
authors.forename: Teet
authors.initials: T
authors.lastname: Velling
authors.forename: Juha
authors.initials: J
authors.lastname: Risteli
authors.forename: Krister
authors.initials: K
authors.lastname: Wennerberg
authors.forename: Deane F
authors.initials: DF
authors.lastname: Mosher
authors.forename: Staffan
authors.initials: S
authors.lastname: Johansson
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry / Q000378:metabolism*; D024061:Collagen Type III / Q000737:chemistry / Q000378:metabolism*; D004622:Embryo, Mammalian; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism; D005347:Fibroblasts / Q000502:physiology; D005353:Fibronectins / Q000172:deficiency / Q000502:physiology*; D038982:Integrin alpha2beta1 / Q000502:physiology*; D016023:Integrins / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D038981:Receptors, Collagen / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D038982:Integrin alpha2beta1; D016023:Integrins; D038981:Receptors, Collagen; D011994:Recombinant Proteins; C467800:integrin alpha11beta1