Vascular dysfunction is a hallmark of many diseases, including coronary heart disease, stroke and diabetes. The underlying mechanisms of these disorders, which are intimately associated with inflammation and oxidative stress caused by excess reactive oxygen species (ROS), have remained elusive. Here we report that ROS are powerful inhibitors of vascular smooth muscle calcium-dependent Slo1 BK or Maxi-K potassium channels, an important physiological determinant of vascular tone. By targeting a cysteine residue near the Ca2+ bowl of the BK α subunit, H2O2 virtually eliminates physiological activation of the channel, with an inhibitory potency comparable to a knockout of the auxiliary subunit BK β1. These results reveal a molecular structural basis for the vascular dysfunction involving oxidative stress and provide a solid rationale for a potential use of BK openers in the prevention and treatment of cardiovascular disorders.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $18.75 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Anderson, R.N. & Smith, B.L. Deaths: leading causes for 2001. Natl. Vital Stat. Rep. 52, 86 (2003).
Halliwell, B. & Gutteridge, J.M.C. Free Radicals in Biology and Medicine (Oxford University Press, New York, 1999).
Ross, R. Atherosclerosis—an inflammatory disease. N. Engl. J. Med. 340, 115–126 (1999).
Hensley, K., Robinson, K.A., Gabbita, S.P., Salsman, S. & Floyd, R.A. Reactive oxygen species, cell signaling, and cell injury. Free Radic. Biol. Med. 28, 1456–1462 (2000).
Clarke, R. & Armitage, J. Antioxidant vitamins and risk of cardiovascular disease. Review of large-scale randomised trials. Cardiovasc. Drugs. Ther. 16, 411–415 (2002).
Fennell, J.P. et al. Adenovirus-mediated overexpression of extracellular superoxide dismutase improves endothelial dysfunction in a rat model of hypertension. Gene Ther. 9, 110–117 (2002).
Nelson, M.T. et al. Relaxation of arterial smooth muscle by calcium sparks. Science 270, 633–637 (1995).
Perez, G.J., Bonev, A.D., Patlak, J.B. & Nelson, M.T. Functional coupling of ryanodine receptors to KCa channels in smooth muscle cells from rat cerebral arteries. J. Gen. Physiol. 113, 229–238 (1999).
ZhuGe, R. et al. Dynamics of signaling between Ca2+ sparks and Ca2+-activated K+ channels studied with a novel image-based method for direct intracellular measurement of ryanodine receptor Ca2+ current. J. Gen. Physiol. 116, 845–864 (2000).
Lohn, M. et al. Regulation of calcium sparks and spontaneous transient outward currents by RyR3 in arterial vascular smooth muscle cells. Circ. Res. 89, 1051–1057 (2001).
Shen, K.Z. et al. Tetraethylammonium block of Slowpoke calcium-activated potassium channels expressed in Xenopus oocytes: evidence for tetrameric channel formation. Pflügers Arch. 426, 440–445 (1994).
Wang, Y.W., Ding, J.P., Xia, X.M. & Lingle, C.J. Consequences of the stoichiometry of Slo1 α and auxiliary β subunits on functional properties of large-conductance Ca2+-activated K+ channels. J. Neurosci. 22, 1550–1561 (2002).
Brenner, R., Jegla, T.J., Wickenden, A., Liu, Y. & Aldrich, R.W. Cloning and functional characterization of novel large conductance calcium-activated potassium channel β subunits, hKCNMB3 and hKCNMB4. J. Biol. Chem. 275, 6453–6461 (2000).
Brenner, R. et al. Vasoregulation by the β1 subunit of the calcium-activated potassium channel. Nature 407, 870–876 (2000).
Plüger, S. et al. Mice with disrupted BK channel β1 subunit gene feature abnormal Ca2+ spark/STOC coupling and elevated blood pressure. Circ. Res. 87, E53–60 (2000).
Patterson, A.J., Henrie-Olson, J. & Brenner, R. Vasoregulation at the molecular level: a role for the β1 subunit of the calcium-activated potassium (BK) channel. Trends Cardiovasc. Med. 12, 78–82 (2002).
Cai, H. & Harrison, D.G. Endothelial dysfunction in cardiovascular diseases: the role of oxidant stress. Circ. Res. 87, 840–844 (2000).
Wang, Z.W., Nara, M., Wang, Y.X. & Kotlikoff, M.I. Redox regulation of large conductance Ca2+-activated K+ channels in smooth muscle cells. J. Gen. Physiol. 110, 35–44 (1997).
Brzezinska, A.K., Gebremedhin, D., Chilian, W.M., Kalyanaraman, B. & Elliott, S.J. Peroxynitrite reversibly inhibits Ca2+-activated K+ channels in rat cerebral artery smooth muscle cells. Am. J. Physiol. 278, H1883–H1890 (2000).
Tang, X.D. et al. Oxidative regulation of large conductance calcium-activated potassium channels. J. Gen. Physiol. 117, 253–274 (2001).
Liu, Y. et al. Peroxynitrite inhibits Ca2+-activated K+ channel activity in smooth muscle of human coronary arterioles. Circ. Res. 91, 1070–1076 (2002).
Soto, M.A., González, C., Lissi, E., Vergara, C. & Latorre, R. Ca2+-activated K+ channel inhibition by reactive oxygen species. Am. J. Physiol. 232, C461–C471 (2002).
Amberg, G.C., Bonev, A.D., Rossow, C.F., Nelson, M.T. & Santana, L.F. Modulation of the molecular composition of large conductance, Ca2+ activated K+ channels in vascular smooth muscle during hypertension. J. Clin. Invest. 112, 717–724 (2003).
Gilbert, D.L. & Colton, C.A. Overview of reactive oxygen species. in Reactive Oxygen Species in Biological Systems (eds. Gilbert, D.L. & Colton, C.A.) 679–695 (Plenum, New York, 1999).
Avdonin, V., Tang, X.D. & Hoshi, T. Stimulatory action of internal protons on Slo1 BK channels. Biophys. J. 84, 2969–2980 (2003).
Tang, X.D. et al. Haem can bind to and inhibit mammalian calcium-dependent Slo1 BK channels. Nature 425, 531–535 (2003).
Lacy, F., Gough, D.A. & Schmid-Schonbein, G.W. Role of xanthine oxidase in hydrogen peroxide production. Free Radic. Biol. Med. 25, 720–727 (1998).
Dröge, W. Free radicals in the physiological control of cell function. Physiol Rev 82, 47–95. (2002).
Dichiara, T.J. & Reinhart, P.H. Redox modulation of hSlo Ca2+-activated K+ channels. J. Neurosci. 17, 4942–4955 (1997).
Jiang, Y. et al. Crystal structure and mechanism of a calcium-gated potassium channel. Nature 417, 515–522. (2002).
Horrigan, F.T. & Aldrich, R.W. Coupling between voltage sensor activation, Ca2+ binding and channel opening in large conductance (BK) potassium channels. J. Gen. Physiol. 120, 267–305 (2002).
Magleby, K.L. Gating mechanism of BK (Slo1) channels: so near, yet so far. J. Gen. Physiol. 121, 81–96 (2003).
Xia, X.M., Zeng, X. & Lingle, C.J. Multiple regulatory sites in large-conductance calcium-activated potassium channels. Nature 418, 880–884 (2002).
Schreiber, M. & Salkoff, L. A novel calcium-sensing domain in the BK channel. Biophys. J. 73, 1355–1363 (1997).
Bian, S., Favre, I. & Moczydlowski, E. Ca2+-binding activity of a COOH-terminal fragment of the Drosophila BK channel involved in Ca2+-dependent activation. Proc. Natl. Acad. Sci. USA 98, 4776–4781 (2001).
Niu, X. & Magleby, K.L. Stepwise contribution of each subunit to the cooperative activation of BK channels by Ca2+. Proc. Natl. Acad. Sci. USA 99, 11441–11446 (2002).
Beckman, J.S. & Koppenol, W.H. Nitric oxide, superoxide, and peroxynitrite: the good, the bad, and ugly. Am. J. Physiol. 271, C1424–C1437 (1996).
Erxleben, C. et al. Interacting effects of N-terminal variation and strex exon splicing on slo potassium channel regulation by calcium, phosphorylation, and oxidation. J. Biol. Chem. 277, 27045–27052 (2002).
Zeng, X.H., Xia, X.M. & Lingle, C.J. Redox-sensitive extracellular gates formed by auxiliary β subunits of calcium-activated potassium channels. Nat. Struct. Biol. 10, 448–454 (2003).
Gribkoff, V.K. et al. Targeting acute ischemic stroke with a calcium-sensitive opener of maxi-K potassium channels. Nat. Med. 7, 471–477 (2001).
Giasson, B.I., Ischiropoulos, H., Lee, V.M. & Trojanowski, J.Q. The relationship between oxidative/nitrative stress and pathological inclusions in Alzheimer's and Parkinson's diseases. Free Radic. Biol. Med. 32, 1264–1275 (2002).
Kaczorowski, G.J., Knaus, H.G., Leonard, R.J., McManus, O.B. & Garcia, M.L. High-conductance calcium-activated potassium channels; structure, pharmacology, and function. J. Bioenerg. Biomembr. 28, 255–267 (1996).
Cui, J. & Aldrich, R.W. Allosteric linkage between voltage and Ca2+-dependent activation of BK-type mSlo1 K+ channels. Biochemistry 39, 15612–15619. (2000).
Zhang, X., Solaro, C.R. & Lingle, C.J. Allosteric regulation of BK channel gating by Ca2+ and Mg2+ through a nonselective, low affinity divalent cation site. J. Gen. Physiol. 118, 607–635 (2001).
Braun, A.F. & Sy, L. Contribution of potential EF hand motifs to the calcium-dependent gating of a mouse brain large conductance, calcium-sensitive K+ channel. J. Physiol. 533, 681–695 (2001).
Bao, L., Rapin, A.M., Holmstrand, E.C. & Cox, D.H. Elimination of the BKCa channel's high-affinity Ca2+ sensitivity. J. Gen. Physiol. 120, 173–189 (2002).
Piskorowski, R. & Aldrich, R.W. Calcium activation of BKCa potassium channels lacking the calcium bowl and RCK domains. Nature 420, 499–502 (2002).
We thank L. Ciali Santarelli for reading of the manuscript, C. Schinstock and M. Hoshi for help with mutant construction, and R. Xu and H. Daggett for cell culture. X.D.T. dedicates this paper to his grandmother who passed away in June 2003. This work was supported in part by the US National Institutes of Health.
About this article
Pflügers Archiv - European Journal of Physiology (2018)
The NOX2-derived reactive oxygen species damaged endothelial nitric oxide system via suppressed BKCa/SKCa in preeclampsia
Hypertension Research (2017)
Acta Pharmacologica Sinica (2014)
Pflügers Archiv - European Journal of Physiology (2012)