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Korean Society for Biochemistry and Molecular Biology (생화학분자생물학회)
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Ethanol inhibits Kv7.2/7.3 channel open probability by reducing the PI(4,5)P2 sensitivity of Kv7.2 subunit

  • Kim, Kwon-Woo (Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST)) ;
  • Suh, Byung-Chang (Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST))
  • Received : 2020.10.23
  • Accepted : 2021.01.05
  • Published : 2021.06.30
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Abstract

Ethanol often causes critical health problems by altering the neuronal activities of the central and peripheral nerve systems. One of the cellular targets of ethanol is the plasma membrane proteins including ion channels and receptors. Recently, we reported that ethanol elevates membrane excitability in sympathetic neurons by inhibiting Kv7.2/7.3 channels in a cell type-specific manner. Even though our studies revealed that the inhibitory effects of ethanol on the Kv7.2/7.3 channel was diminished by the increase of plasma membrane phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), the molecular mechanism of ethanol on Kv7.2/7.3 channel inhibition remains unclear. By investigating the kinetics of Kv7.2/7.3 current in high K+ solution, we found that ethanol inhibited Kv7.2/7.3 channels through a mechanism distinct from that of tetraethylammonium (TEA) which enters into the pore and blocks the gate of the channels. Using a non-stationary noise analysis (NSNA), we demonstrated that the inhibitory effect of ethanol is the result of reduction of open probability (PO) of the Kv7.2/7.3 channel, but not of a single channel current (i) or channel number (N). Finally, ethanol selectively facilitated the kinetics of Kv7.2 current suppression by voltage-sensing phosphatase (VSP)-induced PI(4,5)P2 depletion, while it slowed down Kv7.2 current recovery from the VSP-induced inhibition. Together our results suggest that ethanol regulates neuronal activity through the reduction of open probability and PI(4,5)P2 sensitivity of Kv7.2/7.3 channels.

Keywords

Acknowledgement

This work was supported by grants from the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2019R1A2B5B01070546) and the Basic Science Research Program (2020R1A4A1019436).

References

  1. Harrison NL, Skelly MJ, Grosserode EK et al (2017) Effects of acute alcohol on excitability in the CNS. Neuropharmacology 122, 36-45 https://doi.org/10.1016/j.neuropharm.2017.04.007
  2. Alderazi Y and Brett F (2007) Alcohol and the nervous system. Curr Diagn Pathol 13, 203-209 https://doi.org/10.1016/j.cdip.2007.04.004
  3. Hirota Y (1976) Effect of ethanol on contraction and relaxation of isolated rat ventricular muscle. J Mol Cell Cardiol 8, 727-732 https://doi.org/10.1016/0022-2828(76)90014-6
  4. Harris RA, Trudell JR and Mihic SJ (2008) Ethanol's molecular targets. Sci Signal 1, re7 https://doi.org/10.1126/scisignal.128re7
  5. Kruse SW, Zhao R, Smith DP and Jones DNM (2003) Structure of a specific alcohol-binding site defined by the odorant binding protein LUSH from Drosophila melanogaster. Nat Struct Mol Biol 10, 694-700 https://doi.org/10.1038/nsb960
  6. Bodhinathan K and Slesinger PA (2013) Molecular mechanism underlying ethanol activation of G-protein-gated inwardly rectifying potassium channels. Proc Natl Acad Sci U S A 110, 18309-18314 https://doi.org/10.1073/pnas.1311406110
  7. Koyama S, Brodie MS and Appel SB (2007) Ethanol inhibition of M-current and ethanol-induced direct excitation of ventral tegmental area dopamine neurons. J Neurophysiol 97, 1977-1985 https://doi.org/10.1152/jn.00270.2006
  8. Brown DA and Adams PR (1980) Muscarinic suppression of a novel voltage-sensitive K+ current in a vertebrate neurone. Nature 283, 673-676 https://doi.org/10.1038/283673a0
  9. Greene DL and Hoshi N (2017) Modulation of Kv7 channels and excitability in the brain. Cell Mol Life Sci 74, 495-508 https://doi.org/10.1007/s00018-016-2359-y
  10. Wang H-S, Pan Z, Shi W et al (1998) KCNQ2 and KCNQ3 potassium channel subunits: molecular correlates of the M-channel. Science 282, 1890-1893 https://doi.org/10.1126/science.282.5395.1890
  11. Telezhkin V, Brown DA and Gibb AJ (2012) Distinct subunit contributions to the activation of M-type potassium channels by PI(4,5)P2. J Gen Physiol 140, 41-53 https://doi.org/10.1085/jgp.201210796
  12. Suh BC and Hille B (2002) Recovery from muscarinic modulation of M current channels requires phosphatidylinositol 4,5-bisphosphate synthesis. Neuron 35, 507-520 https://doi.org/10.1016/S0896-6273(02)00790-0
  13. Falkenburger BH, Jensen JB and Hille B (2010) Kinetics of PIP2 metabolism and KCNQ2/3 channel regulation studied with a voltage-sensitive phosphatase in living cells. J Gen Physiol 135, 99-114 https://doi.org/10.1085/jgp.200910345
  14. Zhang Q, Zhou P, Chen Z et al (2013) Dynamic PIP2 interactions with voltage sensor elements contribute to KCNQ2 channel gating. Proc Natl Acad Sci U S A 110, 20093-20098 https://doi.org/10.1073/pnas.1312483110
  15. Choveau FS, De la Rosa V, Bierbower SM, Hernandez CC and Shapiro MS (2018) Phosphatidylinositol 4,5-bisphosphate (PIP2) regulates KCNQ3 K+ channels by interacting with four cytoplasmic channel domains. J Biol Chem 293, 19411-19428 https://doi.org/10.1074/jbc.RA118.005401
  16. Kim KW, Kim K, Lee H and Suh BC (2019) Ethanol elevates excitability of superior cervical ganglion neurons by inhibiting Kv7 channels in a cell type-specific and PI(4,5)P2-dependent manner. Int J Mol Sci 20, 4419 https://doi.org/10.3390/ijms20184419
  17. Hadley JK, Noda M, Selyanko AA et al (2000) Differential tetraethylammonium sensitivity of KCNQ1-4 potassium channels. Br J Pharmacol 129, 413-415 https://doi.org/10.1038/sj.bjp.0703086
  18. Holmgren M, Smith PL and Yellen G (1997) Trapping of organic blockers by closing of voltage-dependent K+ channels: Evidence for a trap door mechanism of activation gating. J Gen Physiol 109, 527-535 https://doi.org/10.1085/jgp.109.5.527
  19. Suh BC and Hille B (2007) Electrostatic Interaction of internal Mg2+ with membrane PIP2 seen with KCNQ K+ channels. J Gen Physiol 130, 241-256 https://doi.org/10.1085/jgp.200709821
  20. Keum D, Kruse M, Kim DI, Hille B and Suh BC (2016) Phosphoinositide 5- and 3-phosphatase activities of a voltage-sensing phosphatase in living cells show identical voltage dependence. Proc Natl Acad Sci U S A 113, E3686-E3695 https://doi.org/10.1073/pnas.1606472113
  21. Jensen JB, Lyssand JS, Hague C and Hille B (2009) Fluorescence changes reveal kinetic steps of muscarinic receptor-mediated modulation of phosphoinositides and Kv7.2/7.3 K+ channels. J Gen Physiol 133, 347-359 https://doi.org/10.1085/jgp.200810075
  22. Kutluay E, Roux B and Heginbotham L (2005) Rapid intra-cellular TEA block of the KcsA potassium channel. Biophys J 88, 1018-1029 https://doi.org/10.1529/biophysj.104.052043
  23. Luzhkov VB and Aqvist J (2001) Mechanisms of tetraethylammonium ion block in the KcsA potassium channel. FEBS Lett 495, 191-196 https://doi.org/10.1016/S0014-5793(01)02381-X
  24. Pegan S, Arrabit C, Slesinger PA and Choe S (2006) Andersen's syndrome mutation effects on the structure and assembly of the cytoplasmic domains of Kir2.1. Biochemistry 45, 8599-8606 https://doi.org/10.1021/bi060653d
  25. Aryal P, Dvir H, Choe S and Slesinger PA (2009) A discrete alcohol pocket involved in GIRK channel activation. Nat Neurosci 12, 988-995 https://doi.org/10.1038/nn.2358
  26. Covarrubias M, Vyas TB, Escobar L and Wei A (1995) Alcohols inhibit a cloned potassium channel at a discrete saturable site. Insights into the molecular basis of general anesthesia. J Biol Chem 270, 19408-19416 https://doi.org/10.1074/jbc.270.33.19408
  27. Villarroel A (1997) Nonstationary noise analysis of M currents simulated and recorded in PC12 cells. J Neurophysiol 77, 2131-2138 https://doi.org/10.1152/jn.1997.77.4.2131
  28. Tatulian L and Brown DA (2003) Effect of the KCNQ potassium channel opener retigabine on single KCNQ2/3 channels expressed in CHO cells. J Physiol 549, 57-63 https://doi.org/10.1113/jphysiol.2003.039842
  29. Schwake M, Pusch M, Kharkovets T and Jentsch TJ (2000) Surface expression and single channel properties of KCNQ2/KCNQ3, M-type K+ channels involved in epilepsy. J Biol Chem 275, 13343-13348 https://doi.org/10.1074/jbc.275.18.13343
  30. Selyanko AA, Hadley JK and Brown DA (2001) Properties of single M-type KCNQ2/KCNQ3 potassium channels expressed in mammalian cells. J Physiol 534, 15-24 https://doi.org/10.1111/j.1469-7793.2001.00015.x
  31. Gao H, Boillat A, Huang D, Liang C, Peers C and Gamper N (2017) Intracellular zinc activates KCNQ channels by reducing their dependence on phosphatidylinositol 4,5-bis-phosphate. Proc Natl Acad Sci U S A 114, E6410-E6419 https://doi.org/10.1073/pnas.1620598114
  32. Zhang H, Craciun LC, Mirshahi T et al (2003) PIP2 activates KCNQ channels, and its hydrolysis underlies receptor-mediated inhibition of M currents. Neuron 37, 963-975 https://doi.org/10.1016/S0896-6273(03)00125-9
  33. Keum D, Baek C, Kim DI, Kweon HJ and Suh BC (2014) Voltage-dependent regulation of CaV2.2 channels by Gq-coupled receptor is facilitated by membrane-localized β subunit. J Gen Physiol 144, 297-309 https://doi.org/10.1085/jgp.201411245
  34. Alvarez O, Gonzalez C and Latorre R (2002) Counting channels: A tutorial guide on ion channel fluctuation analysis. Adv Physio Educ 26, 327-341 https://doi.org/10.1152/advan.00006.2002
  35. Hartveit E and Veruki ML (2007) Studying properties of neurotransmitter receptors by non-stationary noise analysis of spontaneous postsynaptic currents and agonist-evoked responses in outside-out patches. Nat Protoc 2, 434-448 https://doi.org/10.1038/nprot.2007.47
  36. Lim NK, Lam AKM and Dutzler R (2016) Independent activation of ion conduction pores in the double-barreled calcium-activated chloride channel TMEM16A. J Gen Physiol 148, 375-392 https://doi.org/10.1085/jgp.201611650