First Author | Ju H | Year | 1997 |
Journal | J Biol Chem | Volume | 272 |
Issue | 30 | Pages | 18522-5 |
PubMed ID | 9228013 | Mgi Jnum | J:41985 |
Mgi Id | MGI:894903 | Doi | 10.1074/jbc.272.30.18522 |
Citation | Ju H, et al. (1997) Direct interaction of endothelial nitric-oxide synthase and caveolin-1 inhibits synthase activity. J Biol Chem 272(30):18522-5 |
abstractText | Endothelial nitric-oxide synthase (eNOS) and caveolin-1 are associated within endothelial plasmalemmal caveolae. It is not known, however, whether eNOS and caveolin-1 interact directly or indirectly or whether the interaction affects eNOS activity. To answer these questions, we have cloned the bovine caveolin-1 cDNA and have investigated the eNOS-caveolin-1 interaction in an in vitro binding assay system using glutathione S-transferase (GST)-caveolin-1 fusion proteins and baculovirus-expressed bovine eNOS. We have also mapped the domains involved in the interaction using an in vivo yeast two-hybrid system. Results obtained using both in vitro and in vivo protein interaction assays show that both N- and C-terminal cytosolic domains of caveolin-1 interact directly with the eNOS oxygenase domain. Interaction of eNOS with GST-caveolin-1 fusion proteins significantly inhibits enzyme catalytic activity. A synthetic peptide corresponding to caveolin-1 residues 82-101 also potently and reversibly inhibits eNOS activity by interfering with the interaction of the enzyme with Ca2+/calmodulin (CaM). Regulation of eNOS in endothelial cells, therefore, may involve not only positive allosteric regulation by Ca2+/CaM, but also negative allosteric regulation by caveolin-1. |