Green J M, Zheleznyak A, Chung J, Lindberg F P, Sarfati M, Frazier W A, Brown E J
Center for Host/Pathogen Interactions, University of California, San Francisco, San Francisco, California 94143, USA.
J Cell Biol. 1999 Aug 9;146(3):673-82. doi: 10.1083/jcb.146.3.673.
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 alphavbeta3 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 alphavbeta3, is affected by both the multiply membrane spanning domain and cholesterol. These data demonstrate that cholesterol is an essential component of the alphavbeta3/IAP/G protein signaling complex, presumably acting through an effect on IAP conformation.
整合素相关蛋白（CD47）是免疫球蛋白超家族的一种多次跨膜成员，它通过与αvβ3整合素和三聚体G蛋白形成复合物来调节一些依赖黏附的细胞功能。胆固醇对于超分子复合物的三种蛋白质成分的结合及其信号传导至关重要。IAP的多次跨膜结构域是复合物形成所必需的，因为它能结合胆固醇。超分子复合物优先在富含糖鞘脂的膜结构域中形成。单克隆抗体10G2与IAP Ig结构域的结合（先前已证明该结合是与αvβ3结合所必需的）受到多次跨膜结构域和胆固醇的影响。这些数据表明，胆固醇是αvβ3/IAP/G蛋白信号复合物的重要组成部分，可能是通过对IAP构象的影响发挥作用。
