Integrin-associated protein is a receptor for the C-terminal domain of thrombospondin

J Biol Chem. 1996 Jan 5;271(1):21-4. doi: 10.1074/jbc.271.1.21.


The C-terminal "cell-binding domain" (CBD) of thrombospondin-1 (TS1) is a binding site for many cell types. Cell-binding peptides based on the sequence RFYVVM from the CBD of TS1 affinity label a 52-kDa cell surface glycoprotein, which we show is integrin-associated protein (IAP or CD47). IAP associates with alpha v beta 3 and thereby modulates the activity of several integrins. Cells that express IAP bind strongly to TS1, the CBD, and its active cell-binding peptides while IAP negative cells do not. The 52-kDa protein is affinity labeled on IAP-positive but not IAP-negative cells, and monoclonal antibodies against IAP specifically immunoprecipitate the affinity-labeled 52-kDa protein from lysates of IAP-positive cells. Consistent with the association of IAP with alpha v beta 3 integrin, the labeled 52-kDa protein is immunoprecipitated by an anti-alpha v beta 3 antibody. Endothelial cells exhibit chemotaxis toward TS1 (at concentrations above 10 nM) and RFYVVM peptides. Chemotaxis to both agents is specifically inhibited by a function blocking anti-IAP monoclonal antibody. These data establish IAP (CD47) as a receptor for the CBD of TS1 and suggest a mechanism for the well established effects of the CBD on cell motility.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Antigens, CD / metabolism
  • CD47 Antigen
  • Carrier Proteins / metabolism
  • Cell Line
  • Humans
  • Integrins / metabolism*
  • Membrane Glycoproteins / metabolism*
  • Molecular Sequence Data
  • Thrombospondins
  • Tumor Cells, Cultured


  • Antigens, CD
  • CD47 Antigen
  • CD47 protein, human
  • Carrier Proteins
  • Integrins
  • Membrane Glycoproteins
  • Thrombospondins