Na+ Block and Permeation in a K+ Channel of Known Structure

Overview

Journal J Gen Physiol

Specialty Physiology

Date 2002 Aug 29

PMID 12198089

Citations 58

Authors

Crina M Nimigean

Christopher Miller

Affiliations

Soon will be listed here.

Abstract

The effects of intracellular Na(+) were studied on K(+) and Rb(+) currents through single KcsA channels. At low voltage, Na(+) produces voltage-dependent block, which becomes relieved at high voltage by a "punchthrough" mechanism representing Na(+) escaping from its blocking site through the selectivity filter. The Na(+) blocking site is located in the wide, hydrated vestibule, and it displays unexpected selectivity for K(+) and Rb(+) against Na(+). The voltage dependence of Na(+) block reflects coordinated movements of the blocker with permeant ions in the selectivity filter.

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References

Jiang Y, Lee A, Chen J, Cadene M, Chait B, MacKinnon R . Crystal structure and mechanism of a calcium-gated potassium channel. Nature. 2002; 417(6888):515-22. DOI: 10.1038/417515a. View

Chen D, Barcilon V, Eisenberg R . Constant fields and constant gradients in open ionic channels. Biophys J. 1992; 61(5):1372-93. PMC: 1260399. DOI: 10.1016/S0006-3495(92)81944-6. View

Neyton J, Miller C . Potassium blocks barium permeation through a calcium-activated potassium channel. J Gen Physiol. 1988; 92(5):549-67. PMC: 2228918. DOI: 10.1085/jgp.92.5.549. View

Perozo E, Cortes D, Cuello L . Structural rearrangements underlying K+-channel activation gating. Science. 1999; 285(5424):73-8. DOI: 10.1126/science.285.5424.73. View

Jiang Y, Lee A, Chen J, Cadene M, Chait B, MacKinnon R . The open pore conformation of potassium channels. Nature. 2002; 417(6888):523-6. DOI: 10.1038/417523a. View

Andersen . Perspectives on ion permeation . J Gen Physiol. 1999; 113(6):763-4. PMC: 2225605. DOI: 10.1085/jgp.113.6.763. View

Miller C . Ionic hopping defended. J Gen Physiol. 1999; 113(6):783-7. PMC: 2225609. DOI: 10.1085/jgp.113.6.783. View

Zhou M, Mann S, Mackinnon R . Potassium channel receptor site for the inactivation gate and quaternary amine inhibitors. Nature. 2001; 411(6838):657-61. DOI: 10.1038/35079500. View

Cuello L, Romero J, Cortes D, Perozo E . pH-dependent gating in the Streptomyces lividans K+ channel. Biochemistry. 1998; 37(10):3229-36. DOI: 10.1021/bi972997x. View

10.

Neyton J, Miller C . Discrete Ba2+ block as a probe of ion occupancy and pore structure in the high-conductance Ca2+ -activated K+ channel. J Gen Physiol. 1988; 92(5):569-86. PMC: 2228919. DOI: 10.1085/jgp.92.5.569. View

11.

LeMasurier M, Heginbotham L, Miller C . KcsA: it's a potassium channel. J Gen Physiol. 2001; 118(3):303-14. PMC: 2229506. DOI: 10.1085/jgp.118.3.303. View

12.

Zhou Y, Kaufman A, Mackinnon R . Chemistry of ion coordination and hydration revealed by a K+ channel-Fab complex at 2.0 A resolution. Nature. 2001; 414(6859):43-8. DOI: 10.1038/35102009. View

13.

Spassova M, Lu Z . Coupled ion movement underlies rectification in an inward-rectifier K+ channel. J Gen Physiol. 1998; 112(2):211-21. PMC: 2525747. DOI: 10.1085/jgp.112.2.211. View

14.

Miller C . Bis-quaternary ammonium blockers as structural probes of the sarcoplasmic reticulum K+ channel. J Gen Physiol. 1982; 79(5):869-91. PMC: 2215508. DOI: 10.1085/jgp.79.5.869. View

15.

Jiang Y, Mackinnon R . The barium site in a potassium channel by x-ray crystallography. J Gen Physiol. 2000; 115(3):269-72. PMC: 2217209. DOI: 10.1085/jgp.115.3.269. View

16.

Heginbotham L, Odessey E, Miller C . Tetrameric stoichiometry of a prokaryotic K+ channel. Biochemistry. 1997; 36(33):10335-42. DOI: 10.1021/bi970988i. View

17.

Woodhull A . Ionic blockage of sodium channels in nerve. J Gen Physiol. 1973; 61(6):687-708. PMC: 2203489. DOI: 10.1085/jgp.61.6.687. View

18.

Pusch M, Bertorello L, Conti F . Gating and flickery block differentially affected by rubidium in homomeric KCNQ1 and heteromeric KCNQ1/KCNE1 potassium channels. Biophys J. 2000; 78(1):211-26. PMC: 1300631. DOI: 10.1016/S0006-3495(00)76586-6. View

19.

Nonner W, Chen D, Eisenberg B . Progress and prospects in permeation. J Gen Physiol. 1999; 113(6):773-82. PMC: 2225611. DOI: 10.1085/jgp.113.6.773. View

20.

Berneche S, Roux B . Energetics of ion conduction through the K+ channel. Nature. 2001; 414(6859):73-7. DOI: 10.1038/35102067. View