|Title||Deciphering the binding of caveolin-1 to client protein endothelial nitric-oxide synthase (eNOS): scaffolding subdomain identification, interaction modeling, and biological significance|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Trane, AE, Pavlov, D, Sharma, A, Saqib, U, Lau, K, Van Petegem, F, Minshall, RD, Roman, LJ, Bernatchez, PN|
|Journal||Journal of Biological Chemistry|
|ISSN||Print: 0021-9258; Online: 1083-351X|
Caveolin-1 (Cav-1) gene inactivation interferes with caveolae formation and causes a range of cardiovascular and pulmonary complications in vivo. Recent evidence suggests that blunted Cav-1/endothelial nitric-oxide synthase (eNOS) interaction, which occurs specifically in vascular endothelial cells, is responsible for the multiple phenotypes observed in Cav-1-null animals. Under basal conditions, Cav-1 binds eNOS and inhibits nitric oxide (NO) production via the Cav-1 scaffolding domain (CAV; amino acids 82-101). Although we have recently shown that CAV residue Phe-92 is responsible for eNOS inhibition, the "inactive" F92A Cav-1 mutant unexpectedly retains its eNOS binding ability and can increase NO release, indicating the presence of a distinct eNOS binding domain within CAV. Herein, we identified and characterized a small 10-amino acid CAV subsequence (90-99) that accounted for the majority of eNOS association with Cav-1 (Kd = 49 nM), and computer modeling of CAV(90-99) docking to eNOS provides a rationale for the mechanism of eNOS inhibition by Phe-92. Finally, using gene silencing and reconstituted cell systems, we show that intracellular delivery of a F92A CAV(90-99) peptide can promote NO bioavailability in eNOS- and Cav-1-dependent fashions. To our knowledge, these data provide the first detailed analysis of Cav-1 binding to one of its most significant client proteins, eNOS.