S-nitrosylation Inhibits protein kinase C-mediated contraction in mouse aorta.
S-nitrosylation is a ubiquitous protein modification in redox-based signaling and forms S-nitrosothiol from nitric oxide (NO) on cysteine residues. Dysregulation of (S)NO signaling (nitrosative stress) leads to impairment of cellular function. Protein kinase C (PKC) is an important signaling protein that plays a role in the regulation of vascular function, and it is not known whether (S)NO affects PKC's role in vascular reactivity. We hypothesized that S-nitrosylation of PKC in vascular smooth muscle would inhibit its contractile activity. Aortic rings from male C57BL/6 mice were treated with auranofin or 1-chloro-2,4-dinitrobenzene (DNCB) as pharmacological tools, which lead to stabilize S-nitrosylation, and propylamine propylamine NONOate (PANOate) or S-nitrosocysteine (CysNO) as NO donors. Contractile responses of aorta to phorbol-12,13-dibutyrate, a PKC activator, were attenuated by auranofin, DNCB, PANOate, and CysNO. S-nitrosylation of PKCα was increased by auranofin or DNCB and CysNO as compared with control protein. Augmented S-nitrosylation inhibited PKCα activity and subsequently downstream signal transduction. These data suggest that PKC is inactivated by S-nitrosylation, and this modification inhibits PKC-dependent contractile responses. Because S-nitrosylation of PKC inhibits phosphorylation and activation of target proteins related to contraction, this posttranslational modification may be a key player in conditions of decreased vascular reactivity.
Department of Physiology, Medical College of Georgia, Augusta, GA 30912-3000, USA. hchoi@students.mcg.edu
Hyehun
H
Choi
Rita C
RC
Tostes
R Clinton
RC
Webb
D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000502:physiology; D004137:Dinitrochlorobenzene / Q000378:metabolism / Q000494:pharmacology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology; D020030:Nitric Oxide Donors / Q000378:metabolism / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism* / Q000494:pharmacology / Q000502:physiology*; D026403:S-Nitrosothiols / Q000378:metabolism* / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects
D004137:Dinitrochlorobenzene; D020030:Nitric Oxide Donors; D026403:S-Nitrosothiols; D009569:Nitric Oxide; D011493:Protein Kinase C