Beginning on page 673, Green et al. describe the elucidation of a role for cholesterol in the recruitment of integrin-associated protein (IAP) to a receptor signaling complex. Though previous work had shown that cholesterol is required for signaling in several cell types, the new study is the first demonstration of a specific role for cholesterol in receptor complex assembly and the regulation of integrin function.
IAP seems to regulate some of the functions of αvβ3 integrin receptors and has been shown to form a signaling complex with αvβ3 and trimeric G proteins. The authors show that depletion of cholesterol from the cell membrane prevents the formation of this complex and blocks downstream signaling. Depleting cholesterol from IAP also causes a change in the antigenicity of the protein, and expression of chimeric forms of IAP demonstrates that the multiple...
