Skip to main content
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1993 May 15;90(10):4758–4762. doi: 10.1073/pnas.90.10.4758

Gating currents of the cloned delayed-rectifier K+ channel DRK1.

M Taglialatela 1, E Stefani 1
PMCID: PMC46592  PMID: 8506330

Abstract

Gating currents of the cloned delayed-rectifier K+ channel DRK1 expressed in Xenopus oocytes were measured with the open-oocyte Vaseline-gap voltage-clamp technique. DRK1 gating charge had the following salient properties: (i) gating-charge amplitude correlated positively with size of the expressed ionic K+ currents; (ii) the time integral of ON and OFF gating currents was similar, indicating charge conservation and lack of charge immobilization; (iii) the gating-charge activation curve was shallower and had a half-activation potential 15 mV more negative than the activation curve for K+ conductance; (iv) effective valence for the gating current was about two electronic charges per gating subunit; (v) for large depolarizations (to > 0 mV) prominent rising phases were observed during the ON and OFF gating charge, which appeared as shoulders in unsubtracted traces; (vi) for small depolarizing pulses (to < 0 mV) ionic-current activation and deactivation had time constants similar to ON and OFF gating-current decay, respectively; (vii) negative prepulses made more prominent the ON rising phase and delayed ionic and gating currents. The results are consistent with a model for K+ channel activation that has an early slow and/or weakly voltage-dependent transition between early closed states followed by more voltage-dependent transitions between later closed states and a final voltage-independent closed-open transition.

Full text

PDF
4758

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Almers W., Armstrong C. M. Survival of K+ permeability and gating currents in squid axons perfused with K+-free media. J Gen Physiol. 1980 Jan;75(1):61–78. doi: 10.1085/jgp.75.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Almers W. Gating currents and charge movements in excitable membranes. Rev Physiol Biochem Pharmacol. 1978;82:96–190. doi: 10.1007/BFb0030498. [DOI] [PubMed] [Google Scholar]
  3. Armstrong C. M., Bezanilla F. Currents related to movement of the gating particles of the sodium channels. Nature. 1973 Apr 13;242(5398):459–461. doi: 10.1038/242459a0. [DOI] [PubMed] [Google Scholar]
  4. Armstrong C. M., Bezanilla F. Inactivation of the sodium channel. II. Gating current experiments. J Gen Physiol. 1977 Nov;70(5):567–590. doi: 10.1085/jgp.70.5.567. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Armstrong C. M. Time course of TEA(+)-induced anomalous rectification in squid giant axons. J Gen Physiol. 1966 Nov;50(2):491–503. doi: 10.1085/jgp.50.2.491. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bezanilla F., Armstrong C. M. Kinetic properties and inactivation of the gating currents of sodium channels in squid axon. Philos Trans R Soc Lond B Biol Sci. 1975 Jun 10;270(908):449–458. doi: 10.1098/rstb.1975.0022. [DOI] [PubMed] [Google Scholar]
  7. Bezanilla F., Perozo E., Papazian D. M., Stefani E. Molecular basis of gating charge immobilization in Shaker potassium channels. Science. 1991 Nov 1;254(5032):679–683. doi: 10.1126/science.1948047. [DOI] [PubMed] [Google Scholar]
  8. Frech G. C., VanDongen A. M., Schuster G., Brown A. M., Joho R. H. A novel potassium channel with delayed rectifier properties isolated from rat brain by expression cloning. Nature. 1989 Aug 24;340(6235):642–645. doi: 10.1038/340642a0. [DOI] [PubMed] [Google Scholar]
  9. HODGKIN A. L., HUXLEY A. F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. HODGKIN A. L., KATZ B. The effect of sodium ions on the electrical activity of giant axon of the squid. J Physiol. 1949 Mar 1;108(1):37–77. doi: 10.1113/jphysiol.1949.sp004310. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hartmann H. A., Kirsch G. E., Drewe J. A., Taglialatela M., Joho R. H., Brown A. M. Exchange of conduction pathways between two related K+ channels. Science. 1991 Feb 22;251(4996):942–944. doi: 10.1126/science.2000495. [DOI] [PubMed] [Google Scholar]
  12. Kirsch G. E., Drewe J. A., Hartmann H. A., Taglialatela M., de Biasi M., Brown A. M., Joho R. H. Differences between the deep pores of K+ channels determined by an interacting pair of nonpolar amino acids. Neuron. 1992 Mar;8(3):499–505. doi: 10.1016/0896-6273(92)90278-l. [DOI] [PubMed] [Google Scholar]
  13. Kirsch G. E., Taglialatela M., Brown A. M. Internal and external TEA block in single cloned K+ channels. Am J Physiol. 1991 Oct;261(4 Pt 1):C583–C590. doi: 10.1152/ajpcell.1991.261.4.C583. [DOI] [PubMed] [Google Scholar]
  14. MacKinnon R. Determination of the subunit stoichiometry of a voltage-activated potassium channel. Nature. 1991 Mar 21;350(6315):232–235. doi: 10.1038/350232a0. [DOI] [PubMed] [Google Scholar]
  15. Meves H., Vogel W. Slow recovery of sodium current and 'gating current' from inactivation. J Physiol. 1977 May;267(2):395–410. doi: 10.1113/jphysiol.1977.sp011819. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Perozo E., Papazian D. M., Stefani E., Bezanilla F. Gating currents in Shaker K+ channels. Implications for activation and inactivation models. Biophys J. 1992 Apr;62(1):160–171. doi: 10.1016/S0006-3495(92)81802-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Schoppa N. E., McCormack K., Tanouye M. A., Sigworth F. J. The size of gating charge in wild-type and mutant Shaker potassium channels. Science. 1992 Mar 27;255(5052):1712–1715. doi: 10.1126/science.1553560. [DOI] [PubMed] [Google Scholar]
  18. Spires S., Begenisich T. Pharmacological and kinetic analysis of K channel gating currents. J Gen Physiol. 1989 Feb;93(2):263–283. doi: 10.1085/jgp.93.2.263. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Stühmer W., Conti F., Stocker M., Pongs O., Heinemann S. H. Gating currents of inactivating and non-inactivating potassium channels expressed in Xenopus oocytes. Pflugers Arch. 1991 May;418(4):423–429. doi: 10.1007/BF00550881. [DOI] [PubMed] [Google Scholar]
  20. TAYLOR R. E., MOORE J. W., COLE K. S. Analysis of certain errors in squid axon voltage clamp measurements. Biophys J. 1960 Nov;1:161–202. doi: 10.1016/s0006-3495(60)86882-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Taglialatela M., Toro L., Stefani E. Novel voltage clamp to record small, fast currents from ion channels expressed in Xenopus oocytes. Biophys J. 1992 Jan;61(1):78–82. doi: 10.1016/S0006-3495(92)81817-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Taglialatela M., Vandongen A. M., Drewe J. A., Joho R. H., Brown A. M., Kirsch G. E. Patterns of internal and external tetraethylammonium block in four homologous K+ channels. Mol Pharmacol. 1991 Aug;40(2):299–307. [PubMed] [Google Scholar]
  23. Tytgat J., Hess P. Evidence for cooperative interactions in potassium channel gating. Nature. 1992 Oct 1;359(6394):420–423. doi: 10.1038/359420a0. [DOI] [PubMed] [Google Scholar]
  24. VanDongen A. M., Frech G. C., Drewe J. A., Joho R. H., Brown A. M. Alteration and restoration of K+ channel function by deletions at the N- and C-termini. Neuron. 1990 Oct;5(4):433–443. doi: 10.1016/0896-6273(90)90082-q. [DOI] [PubMed] [Google Scholar]
  25. White M. M., Bezanilla F. Activation of squid axon K+ channels. Ionic and gating current studies. J Gen Physiol. 1985 Apr;85(4):539–554. doi: 10.1085/jgp.85.4.539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Yellen G., Jurman M. E., Abramson T., MacKinnon R. Mutations affecting internal TEA blockade identify the probable pore-forming region of a K+ channel. Science. 1991 Feb 22;251(4996):939–942. doi: 10.1126/science.2000494. [DOI] [PubMed] [Google Scholar]
  27. Zagotta W. N., Aldrich R. W. Voltage-dependent gating of Shaker A-type potassium channels in Drosophila muscle. J Gen Physiol. 1990 Jan;95(1):29–60. doi: 10.1085/jgp.95.1.29. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES