Identification of a new biological function for the integrin alpha v beta 3: initiation of fibronectin matrix assembly

Cell Adhes Commun. 1996 Sep;4(3):149-58. doi: 10.3109/15419069609014219.

Abstract

Fibronectin matrix assembly is a complex cellular process initiated by specific fibronectin-binding cell surface receptors. Although the integrin alpha 5 beta 1 has been implicated in the assembly of fibronectin matrices, fibroblastic cells derived from alpha 5 integrin null mutant embryos assemble a fibronectin matrix. Thus, alternative receptors must support this process. Although the platelet integrin alpha IIb beta 3 supports fibronectin matrix assembly, its expression is restricted to platelets. We report that alpha v beta 3 integrin, a fibronectin receptor expressed on many cell types provides an alternative pathway for the assembly of soluble fibronectin into the extracellular matrix. This process occurs independent of alpha 5 beta 1, is also modulated by activation, and the resulting matrix is biochemically indistinguishable from that assembled under the control of alpha 5 beta 1. Matrix assembly requires binding to the RGD site in the 10th type III repeat of fibronectin, as well as the participation of the amino-terminal matrix assembly domain. The participation of two distinct integrins in fibronectin matrix assembly suggests a model for the involvement of integrins in a dual system of extracellular matrix assembly and recognition controlled by intracellular activation of extracellular receptors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antigens, CD / physiology*
  • CHO Cells
  • Cricetinae
  • Extracellular Matrix / ultrastructure*
  • Fibronectins / physiology*
  • Humans
  • Integrin alphaV
  • Integrin beta3
  • Macromolecular Substances
  • Platelet Membrane Glycoproteins / physiology*
  • Receptors, Fibronectin / physiology*
  • Recombinant Proteins

Substances

  • Antibodies, Monoclonal
  • Antigens, CD
  • Fibronectins
  • Integrin alphaV
  • Integrin beta3
  • Macromolecular Substances
  • Platelet Membrane Glycoproteins
  • Receptors, Fibronectin
  • Recombinant Proteins