Polymerization of type I and III collagens is dependent on fibronectin and enhanced by integrins alpha 11beta 1 and alpha 2beta 1.
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.
Velling
Teet
T
Institute of Medical Biochemistry and Microbiology, 75123 Uppsala, Sweden. teet.velling@imbim.uu.se
Risteli
Juha
J
Wennerberg
Krister
K
Mosher
Deane F
DF
Johansson
Staffan
S
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
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