Post-translational mechanisms of endothelial nitric oxide synthase regulation by bradykinin

The endothelial nitric oxide synthase (eNOS) plays a key role in blood pressure regulation and vascular homeostasis. Among the more potent inducers of eNOS activity in vascular endothelial cells is bradykinin (BK). This brief review summarizes the current state of knowledge with regard to regulation of eNOS through several distinct molecular mechanisms, each of which acts in concert with Ca²⁺-calmodulin (CaM) signaling in post-translational activation of eNOS. These mechanisms include alterations in protein-protein interactions with caveolin-1, the BK B2 receptor, and heat shock protein 90 (Hsp90). In addition, BK stimulates an increase in eNOS activity through phosphorylation of the enzyme at three specific amino acid residues as well as through dephosphorylation at a fourth residue.