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Deconstructing voltage sensor function and pharmacology in sodium channels

Abstract

Voltage-activated sodium (Nav) channels are crucial for the generation and propagation of nerve impulses, and as such are widely targeted by toxins and drugs. The four voltage sensors in Nav channels have distinct amino acid sequences, raising fundamental questions about their relative contributions to the function and pharmacology of the channel. Here we use four-fold symmetric voltage-activated potassium (Kv) channels as reporters to examine the contributions of individual S3b–S4 paddle motifs within Nav channel voltage sensors to the kinetics of voltage sensor activation and to forming toxin receptors. Our results uncover binding sites for toxins from tarantula and scorpion venom on each of the four paddle motifs in Nav channels, and reveal how paddle-specific interactions can be used to reshape Nav channel activity. One paddle motif is unique in that it slows voltage sensor activation, and toxins selectively targeting this motif impede Nav channel inactivation. This reporter approach and the principles that emerge will be useful in developing new drugs for treating pain and Nav channelopathies.

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Figure 1: Transfer of the voltage sensor paddle motifs from rNa v 1.2a to K v 2.1.
Figure 2: Sensitivity of rNa v 1.2a paddle chimaeras to extracellular toxins.
Figure 3: Scanning mutagenesis of Na v channel paddle motifs.
Figure 4: Reconstitution of paddle mutants into rNa v 1.2a and their effects on toxin–channel interactions.
Figure 5: Kinetics of opening and closing for rNa v 1.2a/K v 2.1 chimaeras.
Figure 6: Identifying a tarantula toxin selective for the paddle motif in domain IV.

References

  1. Catterall, W. A. From ionic currents to molecular mechanisms: The structure and function of voltage-gated sodium channels. Neuron 26, 13–25 (2000)

    CAS  Article  PubMed  Google Scholar 

  2. Cannon, S. C. Pathomechanisms in channelopathies of skeletal muscle and brain. Annu. Rev. Neurosci. 29, 387–415 (2006)

    CAS  Article  PubMed  Google Scholar 

  3. George, A. L. Inherited disorders of voltage-gated sodium channels. J. Clin. Invest. 115, 1990–1999 (2005)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  4. Cox, J. J. et al. An SCN9A channelopathy causes congenital inability to experience pain. Nature 444, 894–898 (2006)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  5. Fertleman, C. R. et al. SCN9A mutations in paroxysmal extreme pain disorder: Allelic variants underlie distinct channel defects and phenotypes. Neuron 52, 767–774 (2006)

    CAS  Article  PubMed  Google Scholar 

  6. Kaczorowski, G. J., McManus, O. B., Priest, B. T. & Garcia, M. L. Ion channels as drug targets: The next GPCRs. J. Gen. Physiol. 131, 399–405 (2008)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  7. Horn, R., Ding, S. & Gruber, H. J. Immobilizing the moving parts of voltage-gated ion channels. J. Gen. Physiol. 116, 461–476 (2000)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  8. Sheets, M. F., Kyle, J. W., Kallen, R. G. & Hanck, D. A. The Na channel voltage sensor associated with inactivation is localized to the external charged residues of domain IV, S4. Biophys. J. 77, 747–757 (1999)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  9. Yang, N. & Horn, R. Evidence for voltage-dependent S4 movement in sodium channels. Neuron 15, 213–218 (1995)

    CAS  Article  PubMed  Google Scholar 

  10. Chanda, B. & Bezanilla, F. Tracking voltage-dependent conformational changes in skeletal muscle sodium channel during activation. J. Gen. Physiol. 120, 629–645 (2002)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  11. Catterall, W. A. et al. Voltage-gated ion channels and gating modifier toxins. Toxicon 49, 124–141 (2007)

    CAS  Article  PubMed  Google Scholar 

  12. Alabi, A. A., Bahamonde, M. I., Jung, H. J., Kim, J. I. & Swartz, K. J. Portability of paddle motif function and pharmacology in voltage sensors. Nature 450, 370–375 (2007)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  13. Chakrapani, S., Cuello, L. G., Cortes, D. M. & Perozo, E. Structural dynamics of an isolated voltage-sensor domain in a lipid bilayer. Structure 16, 398–409 (2008)

    CAS  PubMed  PubMed Central  Google Scholar 

  14. Jiang, Y. et al. X-ray structure of a voltage-dependent K+ channel. Nature 423, 33–41 (2003)

    ADS  CAS  Article  PubMed  Google Scholar 

  15. Jiang, Y., Ruta, V., Chen, J., Lee, A. & MacKinnon, R. The principle of gating charge movement in a voltage-dependent K+ channel. Nature 423, 42–48 (2003)

    ADS  CAS  Article  PubMed  Google Scholar 

  16. Ruta, V., Chen, J. & MacKinnon, R. Calibrated measurement of gating-charge arginine displacement in the KvAP voltage-dependent K+ channel. Cell 123, 463–475 (2005)

    CAS  Article  PubMed  Google Scholar 

  17. Swartz, K. J. & MacKinnon, R. Mapping the receptor site for hanatoxin, a gating modifier of voltage-dependent K+ channels. Neuron 18, 675–682 (1997)

    CAS  Article  PubMed  Google Scholar 

  18. Swartz, K. J. & MacKinnon, R. Hanatoxin modifies the gating of a voltage-dependent K+ channel through multiple binding sites. Neuron 18, 665–673 (1997)

    CAS  Article  PubMed  Google Scholar 

  19. Li-Smerin, Y. & Swartz, K. J. Gating modifier toxins reveal a conserved structural motif in voltage-gated Ca2+ and K+ channels. Proc. Natl Acad. Sci. USA 95, 8585–8589 (1998)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  20. Li-Smerin, Y. & Swartz, K. J. Localization and molecular determinants of the Hanatoxin receptors on the voltage-sensing domains of a K(+) channel. J. Gen. Physiol. 115, 673–684 (2000)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  21. Lee, H. C., Wang, J. M. & Swartz, K. J. Interaction between extracellular Hanatoxin and the resting conformation of the voltage-sensor paddle in Kv channels. Neuron 40, 527–536 (2003)

    CAS  Article  PubMed  Google Scholar 

  22. Lee, S. Y. & MacKinnon, R. A membrane-access mechanism of ion channel inhibition by voltage sensor toxins from spider venom. Nature 430, 232–235 (2004)

    ADS  CAS  Article  PubMed  Google Scholar 

  23. Milescu, M. et al. Tarantula toxins interact with voltage sensors within lipid membranes. J. Gen. Physiol. 130, 497–511 (2007)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  24. Phillips, L. R. et al. Voltage-sensor activation with a tarantula toxin as cargo. Nature 436, 857–860 (2005)

    ADS  CAS  Article  PubMed  Google Scholar 

  25. Bosmans, F. et al. Four novel tarantula toxins as selective modulators of voltage-gated sodium channel subtypes. Mol. Pharmacol. 69, 419–429 (2006)

    CAS  Article  PubMed  Google Scholar 

  26. Middleton, R. E. et al. Two tarantula peptides inhibit activation of multiple sodium channels. Biochemistry 41, 14734–14747 (2002)

    CAS  Article  PubMed  Google Scholar 

  27. Smith, J. J., Cummins, T. R., Alphy, S. & Blumenthal, K. M. Molecular interactions of the gating modifier toxin ProTx-II with NaV 1.5: Implied existence of a novel toxin binding site coupled to activation. J. Biol. Chem. 282, 12687–12697 (2007)

    CAS  Article  PubMed  Google Scholar 

  28. Sokolov, S., Kraus, R. L., Scheuer, T. & Catterall, W. A. Inhibition of sodium channel gating by trapping the domain II voltage sensor with protoxin II. Mol. Pharmacol. 73, 1020–1028 (2008)

    CAS  Article  PubMed  Google Scholar 

  29. Cahalan, M. D. Modification of sodium channel gating in frog myelinated nerve fibres by Centruroides sculpturatus scorpion venom. J. Physiol. (Lond.) 244, 511–534 (1975)

    CAS  Article  Google Scholar 

  30. Koppenhofer, E. & Schmidt, H. Effect of scorpion venom on ionic currents of the node of Ranvier. II. Incomplete sodium inactivation. Pflugers Arch. 303, 150–161 (1968)

    CAS  Article  PubMed  Google Scholar 

  31. Rogers, J. C., Qu, Y., Tanada, T. N., Scheuer, T. & Catterall, W. A. Molecular determinants of high affinity binding of alpha-scorpion toxin and sea anemone toxin in the S3-S4 extracellular loop in domain IV of the Na+ channel alpha subunit. J. Biol. Chem. 271, 15950–15962 (1996)

    CAS  Article  PubMed  Google Scholar 

  32. Cestele, S. et al. Voltage sensor-trapping: Enhanced activation of sodium channels by beta-scorpion toxin bound to the S3-S4 loop in domain II. Neuron 21, 919–931 (1998)

    CAS  Article  PubMed  Google Scholar 

  33. Cestele, S. et al. Structure and function of the voltage sensor of sodium channels probed by a beta-scorpion toxin. J. Biol. Chem. 281, 21332–21344 (2006)

    CAS  Article  PubMed  Google Scholar 

  34. Cohen, L. et al. Direct evidence that receptor site-4 of sodium channel gating modifiers is not dipped in the phospholipid bilayer of neuronal membranes. J. Biol. Chem. 281, 20673–20679 (2006)

    CAS  Article  PubMed  Google Scholar 

  35. Tejedor, F. J. & Catterall, W. A. Site of covalent attachment of alpha-scorpion toxin derivatives in domain I of the sodium channel alpha subunit. Proc. Natl Acad. Sci. USA 85, 8742–8746 (1988)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  36. Marcotte, P., Chen, L. Q., Kallen, R. G. & Chahine, M. Effects of Tityus serrulatus scorpion toxin gamma on voltage-gated Na+ channels. Circ. Res. 80, 363–369 (1997)

    CAS  Article  PubMed  Google Scholar 

  37. Campos, F. V., Chanda, B., Beirao, P. S. & Bezanilla, F. Beta-scorpion toxin modifies gating transitions in all four voltage sensors of the sodium channel. J. Gen. Physiol. 130, 257–268 (2007)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  38. Campos, F. V., Chanda, B., Beirao, P. S. & Bezanilla, F. Alpha-scorpion toxin impairs a conformational change that leads to fast inactivation of muscle sodium channels. J. Gen. Physiol. 132, 251–263 (2008)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  39. Cha, A., Ruben, P. C., George, A. L., Fujimoto, E. & Bezanilla, F. Voltage sensors in domains III and IV, but not I and II, are immobilized by Na+ channel fast inactivation. Neuron 22, 73–87 (1999)

    CAS  Article  PubMed  Google Scholar 

  40. Sheets, M. F., Kyle, J. W. & Hanck, D. A. The role of the putative inactivation lid in sodium channel gating current immobilization. J. Gen. Physiol. 115, 609–620 (2000)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  41. Banerjee, A. & MacKinnon, R. Inferred motions of the S3a helix during voltage-dependent K+ channel gating. J. Mol. Biol. 381, 569–580 (2008)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  42. Ruta, V., Jiang, Y., Lee, A., Chen, J. & MacKinnon, R. Functional analysis of an archaebacterial voltage-dependent K+ channel. Nature 422, 180–185 (2003)

    ADS  CAS  Article  PubMed  Google Scholar 

  43. Herrington, J. et al. Blockers of the delayed-rectifier potassium current in pancreatic beta-cells enhance glucose-dependent insulin secretion. Diabetes 55, 1034–1042 (2006)

    CAS  Article  PubMed  Google Scholar 

  44. Lee, C. W. et al. Solution structure and functional characterization of SGTx1, a modifier of Kv2.1 channel gating. Biochemistry 43, 890–897 (2004)

    CAS  Article  PubMed  Google Scholar 

  45. Armstrong, C. M. Na channel inactivation from open and closed states. Proc. Natl Acad. Sci. USA 103, 17991–17996 (2006)

    ADS  CAS  Article  PubMed  PubMed Central  Google Scholar 

  46. Chanda, B., Asamoah, O. K. & Bezanilla, F. Coupling interactions between voltage sensors of the sodium channel as revealed by site-specific measurements. J. Gen. Physiol. 123, 217–230 (2004)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  47. Wan, X., Chen, S., Sadeghpour, A., Wang, Q. & Kirsch, G. E. Accelerated inactivation in a mutant Na(+) channel associated with idiopathic ventricular fibrillation. Am. J. Physiol. Heart Circ. Physiol. 280, H354–H360 (2001)

    CAS  Article  PubMed  Google Scholar 

  48. Bennett, P. B., Yazawa, K., Makita, N. & George, A. L. Molecular mechanism for an inherited cardiac arrhythmia. Nature 376, 683–685 (1995)

    ADS  CAS  Article  PubMed  Google Scholar 

  49. Spampanato, J., Escayg, A., Meisler, M. H. & Goldin, A. L. Generalized epilepsy with febrile seizures plus type 2 mutation W1204R alters voltage-dependent gating of Na(v)1.1 sodium channels. Neuroscience 116, 37–48 (2003)

    CAS  Article  PubMed  Google Scholar 

  50. Bendahhou, S., Cummins, T. R., Tawil, R., Waxman, S. G. & Ptacek, L. J. Activation and inactivation of the voltage-gated sodium channel: Role of segment S5 revealed by a novel hyperkalaemic periodic paralysis mutation. J. Neurosci. 19, 4762–4771 (1999)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  51. 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 340, 642–645 (1989)

    ADS  CAS  Article  PubMed  Google Scholar 

  52. Stuhmer, W. et al. Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain. EMBO J. 8, 3235–3244 (1989)

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  53. Tempel, B. L., Papazian, D. M., Schwarz, T. L., Jan, Y. N. & Jan, L. Y. Sequence of a probable potassium channel component encoded at Shaker locus of Drosophila. Science 237, 770–775 (1987)

    ADS  CAS  Article  PubMed  Google Scholar 

  54. Auld, V. J. et al. A rat brain Na+ channel alpha subunit with novel gating properties. Neuron 1, 449–461 (1988)

    CAS  Article  PubMed  Google Scholar 

  55. Trimmer, J. S. et al. Primary structure and functional expression of a mammalian skeletal muscle sodium channel. Neuron 3, 33–49 (1989)

    CAS  Article  PubMed  Google Scholar 

  56. Garcia, M. L., Garcia-Calvo, M., Hidalgo, P., Lee, A. & MacKinnon, R. Purification and characterization of three inhibitors of voltage-dependent K+ channels from Leiurus quinquestriatus var. hebraeus venom. Biochemistry 33, 6834–6839 (1994)

    CAS  Article  PubMed  Google Scholar 

  57. Hoshi, T., Zagotta, W. N. & Aldrich, R. W. Biophysical and molecular mechanisms of Shaker potassium channel inactivation. Science 250, 533–538 (1990)

    ADS  CAS  Article  PubMed  Google Scholar 

  58. Swartz, K. J. & MacKinnon, R. An inhibitor of the Kv2.1 potassium channel isolated from the venom of a Chilean tarantula. Neuron 15, 941–949 (1995)

    CAS  Article  PubMed  Google Scholar 

  59. Jung, H. J. et al. Solution structure and lipid membrane partitioning of VSTx1, an inhibitor of the KvAP potassium channel. Biochemistry 44, 6015–6023 (2005)

    CAS  Article  PubMed  Google Scholar 

  60. Ceard, B., De Lima, M. E., Bougis, P. E. & Martin-Eauclaire, M. F. Purification of the main beta-toxin from Tityus serrulatus scorpion venom using high-performance liquid chromatography. Toxicon 30, 105–110 (1992)

    CAS  Article  PubMed  Google Scholar 

  61. Martin, M. F., Rochat, H., Marchot, P. & Bougis, P. E. Use of high performance liquid chromatography to demonstrate quantitative variation in components of venom from the scorpion Androctonus australis hector . Toxicon 25, 569–573 (1987)

    CAS  Article  PubMed  Google Scholar 

  62. Wang, G. K., Quan, C., Seaver, M. & Wang, S. Y. Modification of wild-type and batrachotoxin-resistant muscle mu1 Na+ channels by veratridine. Pflugers Arch. 439, 705–713 (2000)

    CAS  PubMed  Google Scholar 

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Acknowledgements

We thank J. W. Kyle, D. A. Hanck and A. L. Goldin for the rNav1.2a, rNav1.4 and β1 clones, C. Deutsch for Kv1.3, M. M. Smith for GxTx-1E, K. M. Blumenthal and J. B. Herrington for ProTx-II, L. D. Possani for a sample of TsVII, the NINDS DNA sequencing facility for DNA sequencing, and the NINDS protein sequencing facility for mass spectrometry and peptide sequencing. We thank A. A. Alabi for helping with Kv and Nav channel alignments and T.-H. Chang for assistance with Nav channel mutants. We also thank A. A. Alabi, M. Holmgren, M. Mayer, M. Milescu, J. Mindell, A. Plested, S. Silberberg and members of the Swartz laboratory for discussions. This work was supported by the Intramural Research Program of the NINDS, NIH (K.J.S.) and by an NIH-FWO postdoctoral fellowship (F.B.).

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Bosmans, F., Martin-Eauclaire, MF. & Swartz, K. Deconstructing voltage sensor function and pharmacology in sodium channels. Nature 456, 202–208 (2008). https://doi.org/10.1038/nature07473

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