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© The Rockefeller University Press,
0021-9525/1999//673 $5.00
The Journal of Cell Biology, Volume 146, Number 3,
, 1999 673-682
Original Article |
Role of Cholesterol in Formation and Function of a Signaling Complex Involving
vβ3, Integrin-Associated Protein (Cd47), and Heterotrimeric G Proteins
ebrown{at}medicine.ucsf.edu
Integrin-associated protein (CD47) is a multiply membrane spanning member of the immunoglobulin superfamily that regulates some adhesion-dependent cell functions through formation of a complex with
vβ3 integrin and trimeric G proteins. Cholesterol is critical for the association of the three protein components of the supramolecular complex and for its signaling. The multiply membrane spanning domain of IAP is required for complex formation because it binds cholesterol. The supramolecular complex forms preferentially in glycosphingolipid-enriched membrane domains. Binding of mAb 10G2 to the IAP Ig domain, previously shown to be required for association with
vβ3, is affected by both the multiply membrane spanning domain and cholesterol. These data demonstrate that cholesterol is an essential component of the
vβ3/IAP/G protein signaling complex, presumably acting through an effect on IAP conformation.
Key Words: cholesterol integrin cell adhesion plasma membrane vitronectin
© 1999 The Rockefeller University Press
1.used in this paper: DIG, detergent-insoluble glycolipid domain; GPI, glycosylphosphatidylinositol; IAP, integrin-associated protein (CD47); MβCD, methyl-β-cyclodextrin; MMS, multiply membrane spanning; TSP, thrombospondin; Vn, vitronectin
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