These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Thrombospondin-1 acts via IAP/CD47 to synergize with collagen in alpha2beta1-mediated platelet activation.
    Author: Chung J, Wang XQ, Lindberg FP, Frazier WA.
    Journal: Blood; 1999 Jul 15; 94(2):642-8. PubMed ID: 10397731.
    Abstract:
    Integrin-associated protein (IAP; or CD47) is a receptor for the cell binding domain (CBD) of thrombospondin-1 (TS1). In platelets, IAP associates with and regulates the function of alphaIIbbeta3 integrin (Chung et al, J Biol Chem 272:14740, 1997). We test here the possibility that CD47 may also modulate the function of platelet integrin alpha2beta1, a collagen receptor. The CD47 agonist peptide, 4N1K (KRFYVVMWKK), derived from the CBD, synergizes with soluble collagen in aggregating platelet-rich plasma. 4N1K and intact TS1 also induce the aggregation of washed, unstirred platelets on immobilized collagen with a rapid increase in tyrosine phosphorylation. The effects of TS1 and 4N1K on platelet aggregation are absolutely dependent on IAP, as shown by the use of platelets from IAP-/- mice. Prostaglandin E1 (PGE1) prevents 4N1K-dependent aggregation on immobilized collagen but does not inhibit the 4N1K peptide stimulation of alpha2beta1-dependent platelet spreading. Finally, a detergent-stable, physical association of IAP and alpha2beta1 integrin is detected by coimmunoprecipitation. These results imply a role for IAP and TS1 in the early activation of platelets upon adhesion to collagen.
    [Abstract] [Full Text] [Related] [New Search]