Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.6.1.2 (guanylate cyclase)
 8,497 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Xenopus oocytes expressing slowly activating IsK channels superfusion with the nitroso-donor S-Nitroso-Cysteine (SNOC) resulted in an increase of IsK, which was greatly enhanced when the amino acid-exchanger rBAT was coexpressed. The effects of SNOC on IsK could not be prevented by the guanylate cyclase inhibitor LY-83,583 and the cGMP kinase inhibitor H8, but was abolished in the presence of staurosporine. SNOC also increased the currents induced by the expression of protein mutants lacking intracellular sites, previously described to be involved in IsK regulation by oxidation and phosphorylation. These data suggest that the NO-donor SNOC regulates IsK indirectly via a cGMP independent, but staurosporine sensitive, pathway.
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PMID:The nitroso-donor S-nitroso-cysteine regulates IsK expressed in Xenopus oocytes via a c-GMP independent mechanism. 785 64

Nitric oxide (NO) is a gaseous signal mediator showing numerous important biological effects. NO has been shown in many instances to exhibit its action via the protein S-nitrosylation mechanism, in which binding of NO to Cys residues regulate protein function independently of activation of soluble guanylate cyclase. The direct link between protein S-nitrosylation and functional modulation, however, has been demonstrated only in limited examples. Furthermore, although most proteins have more than one Cys residue, the mechanism by which a certain Cys becomes a specific target residue of S-nitrosylation is poorly understood. We have previously reported that NO regulates currents through the cardiac slowly activating delayed rectifier potassium channel (I(Ks)) irrespective of soluble guanylate cyclase activation. Here we demonstrate using a biotin-switch assay that NO induced S-nitrosylation of the alpha-subunit of the I(Ks) channel, KCNQ1, at Cys(445) in the C terminus. A redox motif flanking Cys(445) and the interaction of KCNQ1 with calmodulin are required for preferential S-nitrosylation of Cys(445). A patch clamp experiment shows that S-nitrosylation of Cys(445) modulates the KCNQ1/KCNE1 channel function. Our data provide a molecular basis of NO-mediated regulation of the I(Ks) channel. This novel regulatory mechanism of the I(Ks) channel may play a role in previously demonstrated NO-mediated phenomenon in cardiac electrophysiology, including shortening in action potential duration in response to intracellular Ca(2+) or sex hormones.
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PMID:Redox- and calmodulin-dependent S-nitrosylation of the KCNQ1 channel. 1912 72