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. 1995 Mar 1;105(3):309–328. doi: 10.1085/jgp.105.3.309

Regulation of voltage dependence of the KAT1 channel by intracellular factors

PMCID: PMC2216946  PMID: 7769379

Abstract

The KAT1 channel is a hyperpolarization-activated K+ channel cloned from the higher plant Arabidopsis. The deduced amino acid sequence suggests that its structural organization is similar to that of the Shaker-like K+ channel activated by depolarization. Electrophysiological properties of the KAT1 channel expressed in Xenopus oocytes indicate that voltage-dependent activation of the KAT1 channel is not caused by the divalent ion block and that it is intrinsic to the channel. Activity of the KAT1 channel progressively decreases upon patch excision. This rundown of the channel is accompanied by a large shift in the voltage dependence of the channel to a more negative direction. The voltage dependence is also regulated by pH, ATP, and cGMP.

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Selected References

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  1. Anderson J. A., Huprikar S. S., Kochian L. V., Lucas W. J., Gaber R. F. Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1992 May 1;89(9):3736–3740. doi: 10.1073/pnas.89.9.3736. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Anumonwo J. M., Delmar M., Jalife J. Electrophysiology of single heart cells from the rabbit tricuspid valve. J Physiol. 1990 Jun;425:145–167. doi: 10.1113/jphysiol.1990.sp018097. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bean B. P. Whole-cell recording of calcium channel currents. Methods Enzymol. 1992;207:181–193. doi: 10.1016/0076-6879(92)07013-e. [DOI] [PubMed] [Google Scholar]
  4. Brüggemann A., Pardo L. A., Stühmer W., Pongs O. Ether-à-go-go encodes a voltage-gated channel permeable to K+ and Ca2+ and modulated by cAMP. Nature. 1993 Sep 30;365(6445):445–448. doi: 10.1038/365445a0. [DOI] [PubMed] [Google Scholar]
  5. Burton F. L., Hutter O. F. Sensitivity to flow of intrinsic gating in inwardly rectifying potassium channel from mammalian skeletal muscle. J Physiol. 1990 May;424:253–261. doi: 10.1113/jphysiol.1990.sp018065. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Cohen I. S., DiFrancesco D., Mulrine N. K., Pennefather P. Internal and external K+ help gate the inward rectifier. Biophys J. 1989 Jan;55(1):197–202. doi: 10.1016/S0006-3495(89)82792-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Guy H. R., Durell S. R., Warmke J., Drysdale R., Ganetzky B. Similarities in amino acid sequences of Drosophila eag and cyclic nucleotide-gated channels. Science. 1991 Nov 1;254(5032):730–730. doi: 10.1126/science.1658932. [DOI] [PubMed] [Google Scholar]
  8. Ho K., Nichols C. G., Lederer W. J., Lytton J., Vassilev P. M., Kanazirska M. V., Hebert S. C. Cloning and expression of an inwardly rectifying ATP-regulated potassium channel. Nature. 1993 Mar 4;362(6415):31–38. doi: 10.1038/362031a0. [DOI] [PubMed] [Google Scholar]
  9. Horn R., Korn S. J. Prevention of rundown in electrophysiological recording. Methods Enzymol. 1992;207:149–155. doi: 10.1016/0076-6879(92)07010-l. [DOI] [PubMed] [Google Scholar]
  10. Hoshi T., Zagotta W. N., Aldrich R. W. Biophysical and molecular mechanisms of Shaker potassium channel inactivation. Science. 1990 Oct 26;250(4980):533–538. doi: 10.1126/science.2122519. [DOI] [PubMed] [Google Scholar]
  11. Hoshi T., Zagotta W. N., Aldrich R. W. Shaker potassium channel gating. I: Transitions near the open state. J Gen Physiol. 1994 Feb;103(2):249–278. doi: 10.1085/jgp.103.2.249. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kramer R. H. Patch cramming: monitoring intracellular messengers in intact cells with membrane patches containing detector ion channels. Neuron. 1990 Mar;4(3):335–341. doi: 10.1016/0896-6273(90)90046-i. [DOI] [PubMed] [Google Scholar]
  13. Kubo Y., Baldwin T. J., Jan Y. N., Jan L. Y. Primary structure and functional expression of a mouse inward rectifier potassium channel. Nature. 1993 Mar 11;362(6416):127–133. doi: 10.1038/362127a0. [DOI] [PubMed] [Google Scholar]
  14. Kubo Y., Reuveny E., Slesinger P. A., Jan Y. N., Jan L. Y. Primary structure and functional expression of a rat G-protein-coupled muscarinic potassium channel. Nature. 1993 Aug 26;364(6440):802–806. doi: 10.1038/364802a0. [DOI] [PubMed] [Google Scholar]
  15. 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]
  16. Marom S., Goldstein S. A., Kupper J., Levitan I. B. Mechanism and modulation of inactivation of the Kv3 potassium channel. Receptors Channels. 1993;1(1):81–88. [PubMed] [Google Scholar]
  17. Matsuda H. Magnesium gating of the inwardly rectifying K+ channel. Annu Rev Physiol. 1991;53:289–298. doi: 10.1146/annurev.ph.53.030191.001445. [DOI] [PubMed] [Google Scholar]
  18. Pennefather P., Oliva C., Mulrine N. Origin of the potassium and voltage dependence of the cardiac inwardly rectifying K-current (IK1). Biophys J. 1992 Feb;61(2):448–462. doi: 10.1016/S0006-3495(92)81850-7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Ruppersberg J. P., Schröter K. H., Sakmann B., Stocker M., Sewing S., Pongs O. Heteromultimeric channels formed by rat brain potassium-channel proteins. Nature. 1990 Jun 7;345(6275):535–537. doi: 10.1038/345535a0. [DOI] [PubMed] [Google Scholar]
  20. Salkoff L., Baker K., Butler A., Covarrubias M., Pak M. D., Wei A. An essential 'set' of K+ channels conserved in flies, mice and humans. Trends Neurosci. 1992 May;15(5):161–166. doi: 10.1016/0166-2236(92)90165-5. [DOI] [PubMed] [Google Scholar]
  21. Schachtman D. P., Schroeder J. I., Lucas W. J., Anderson J. A., Gaber R. F. Expression of an inward-rectifying potassium channel by the Arabidopsis KAT1 cDNA. Science. 1992 Dec 4;258(5088):1654–1658. doi: 10.1126/science.8966547. [DOI] [PubMed] [Google Scholar]
  22. 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]
  23. Schroeder J. I. K+ transport properties of K+ channels in the plasma membrane of Vicia faba guard cells. J Gen Physiol. 1988 Nov;92(5):667–683. doi: 10.1085/jgp.92.5.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Schroeder J. I., Raschke K., Neher E. Voltage dependence of K channels in guard-cell protoplasts. Proc Natl Acad Sci U S A. 1987 Jun;84(12):4108–4112. doi: 10.1073/pnas.84.12.4108. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Sentenac H., Bonneaud N., Minet M., Lacroute F., Salmon J. M., Gaymard F., Grignon C. Cloning and expression in yeast of a plant potassium ion transport system. Science. 1992 May 1;256(5057):663–665. doi: 10.1126/science.1585180. [DOI] [PubMed] [Google Scholar]
  26. Warmke J., Drysdale R., Ganetzky B. A distinct potassium channel polypeptide encoded by the Drosophila eag locus. Science. 1991 Jun 14;252(5012):1560–1562. doi: 10.1126/science.1840699. [DOI] [PubMed] [Google Scholar]
  27. Zagotta W. N., Hoshi T., Aldrich R. W. Gating of single Shaker potassium channels in Drosophila muscle and in Xenopus oocytes injected with Shaker mRNA. Proc Natl Acad Sci U S A. 1989 Sep;86(18):7243–7247. doi: 10.1073/pnas.86.18.7243. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Zagotta W. N., Hoshi T., Aldrich R. W. Restoration of inactivation in mutants of Shaker potassium channels by a peptide derived from ShB. Science. 1990 Oct 26;250(4980):568–571. doi: 10.1126/science.2122520. [DOI] [PubMed] [Google Scholar]
  29. Zagotta W. N., Hoshi T., Aldrich R. W. Shaker potassium channel gating. III: Evaluation of kinetic models for activation. J Gen Physiol. 1994 Feb;103(2):321–362. doi: 10.1085/jgp.103.2.321. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Zagotta W. N., Hoshi T., Dittman J., Aldrich R. W. Shaker potassium channel gating. II: Transitions in the activation pathway. J Gen Physiol. 1994 Feb;103(2):279–319. doi: 10.1085/jgp.103.2.279. [DOI] [PMC free article] [PubMed] [Google Scholar]

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