JCI Insight (Sep 2020)

Voltage-gated potassium channel proteins and stereoselective S-nitroso-l-cysteine signaling

  • Benjamin Gaston,
  • Laura Smith,
  • Jürgen Bosch,
  • James Seckler,
  • Diana Kunze,
  • Janna Kiselar,
  • Nadzeya Marozkina,
  • Craig A. Hodges,
  • Patrick Wintrobe,
  • Kellen McGee,
  • Tatiana S. Morozkina,
  • Spencer T. Burton,
  • Tristan Lewis,
  • Timothy Strassmaier,
  • Paulina Getsy,
  • James N. Bates,
  • Stephen J. Lewis

Journal volume & issue
Vol. 5, no. 18

Abstract

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S-nitroso-l-cysteine (L-CSNO) behaves as a ligand. Its soluble guanylate cyclase–independent (sGC-independent) effects are stereoselective — that is, not recapitulated by S-nitroso-d-cysteine (D-CSNO) — and are inhibited by chemical congeners. However, candidate L-CSNO receptors have not been identified. Here, we have used 2 complementary affinity chromatography assays — followed by unbiased proteomic analysis — to identify voltage-gated K+ channel (Kv) proteins as binding partners for L-CSNO. Stereoselective L-CSNO–Kv interaction was confirmed structurally and functionally using surface plasmon resonance spectroscopy; hydrogen deuterium exchange; and, in Kv1.1/Kv1.2/Kvβ2-overexpressing cells, patch clamp assays. Remarkably, these sGC-independent L-CSNO effects did not involve S-nitrosylation of Kv proteins. In isolated rat and mouse respiratory control (petrosyl) ganglia, L-CSNO stereoselectively inhibited Kv channel function. Genetic ablation of Kv1.1 prevented this effect. In intact animals, L-CSNO injection at the level of the carotid body dramatically and stereoselectively increased minute ventilation while having no effect on blood pressure; this effect was inhibited by the L-CSNO congener S-methyl-l-cysteine. Kv proteins are physiologically relevant targets of endogenous L-CSNO. This may be a signaling pathway of broad relevance.

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