Dataset Information

Calmodulin-induced structural changes in endothelial nitric oxide synthase.

ABSTRACT: We have derived structures of intact calmodulin (CaM)-free and CaM-bound endothelial nitric oxide synthase (eNOS) by reconstruction from cryo-electron micrographs. The CaM-free reconstruction is well fitted by the oxygenase domain dimer, but the reductase domains are not visible, suggesting they are mobile and thus delocalized. Additional protein is visible in the CaM-bound reconstruction, concentrated in volumes near two basic patches on each oxygenase domain. One of these corresponds with a presumptive docking site for the reductase domain FMN-binding module. The other is proposed to correspond with a docking site for CaM. A model is suggested in which CaM binding and docking position the reductase domains near the oxygenase domains and promote docking of the FMN-binding modules required for electron transfer.

SUBMITTER: Persechini A

PROVIDER: S-EPMC3569036 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Calmodulin-induced structural changes in endothelial nitric oxide synthase.

Persechini Anthony A Tran Quang-Kim QK Black D J DJ Gogol Edward P EP

FEBS letters 20121222 3

We have derived structures of intact calmodulin (CaM)-free and CaM-bound endothelial nitric oxide synthase (eNOS) by reconstruction from cryo-electron micrographs. The CaM-free reconstruction is well fitted by the oxygenase domain dimer, but the reductase domains are not visible, suggesting they are mobile and thus delocalized. Additional protein is visible in the CaM-bound reconstruction, concentrated in volumes near two basic patches on each oxygenase domain. One of these corresponds with a pr ...[more]

PMID: 23266515

Similar Datasets

Project description:OBJECTIVE:Impaired endothelial cell (EC) autophagy compromises shear stress-induced nitric oxide (NO) generation. We determined the responsible mechanism. APPROACH AND RESULTS:On autophagy compromise in bovine aortic ECs exposed to shear stress, a decrease in glucose uptake and EC glycolysis attenuated ATP production. We hypothesized that decreased glycolysis-dependent purinergic signaling via P2Y1 (P2Y purinoceptor 1) receptors, secondary to impaired autophagy in ECs, prevents shear-induced phosphorylation of eNOS (endothelial nitric oxide synthase) at its positive regulatory site S1117 (p-eNOSS1177) and NO generation. Maneuvers that restore glucose transport and glycolysis (eg, overexpression of GLUT1 [glucose transporter 1]) or purinergic signaling (eg, addition of exogenous ADP) rescue shear-induced p-eNOSS1177 and NO production in ECs with impaired autophagy. Conversely, inhibiting glucose transport via GLUT1 small interfering RNA, blocking purinergic signaling via ectonucleotidase-mediated ATP/ADP degradation (eg, apyrase), or inhibiting P2Y1 receptors using pharmacological (eg, MRS2179 [2'-deoxy-N6-methyladenosine 3',5'-bisphosphate tetrasodium salt]) or genetic (eg, P2Y1-receptor small interfering RNA) procedures inhibit shear-induced p-eNOSS1177 and NO generation in ECs with intact autophagy. Supporting a central role for PKC?T505 (protein kinase C delta T505) in relaying the autophagy-dependent purinergic-mediated signal to eNOS, we find that (1) shear stress-induced activating phosphorylation of PKC?T505 is negated by inhibiting autophagy, (2) shear-induced p-eNOSS1177 and NO generation are restored in autophagy-impaired ECs via pharmacological (eg, bryostatin) or genetic (eg, constitutively active PKC?) activation of PKC?T505, and (3) pharmacological (eg, rottlerin) and genetic (eg, PKC? small interfering RNA) PKC? inhibition prevents shear-induced p-eNOSS1177 and NO generation in ECs with intact autophagy. Key nodes of dysregulation in this pathway on autophagy compromise were revealed in human arterial ECs. CONCLUSIONS:Targeted reactivation of purinergic signaling and PKC? has strategic potential to restore compromised NO generation in pathologies associated with suppressed EC autophagy.

Dataset Information

Calmodulin-induced structural changes in endothelial nitric oxide synthase.

Publications

Calmodulin-induced structural changes in endothelial nitric oxide synthase.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets