Pflügers Archiv

, Volume 427, Issue 5–6, pp 399–405 | Cite as

Kinetic mode switch of rat brain IIA Na channels in Xenopus oocytes excised macropatches

  • Andrea Fleig
  • Peter C. Ruben
  • Martin D. Rayner
Molecular and Cellular Physiology


Na currents recorded from inside-out macropatches excised from Xenopus oocytes expressing the α subunit of the rat brain Na channel IIA show at least two distinguishable components in their inactivation time course, with time constants differing about tenfold (τh1 = approx. 150 μs and τh2 = approx. 2 ms). In excised patches, the inactivation properties of Na currents changed with time, favoring the faster inactivation kinetics. Analysis of the fast and slow current kinetics shows that only the relative magnitudes of τh1 and τh2 components are altered without significant changes in the time constants of activation or inactivation. In addition, voltage dependence of both activation and steady-state inactivation of Na currents are shifted to more negative potentials in patches with predominantly fast inactivation, although reversal potentials and valences remained unaltered. We conclude that the two inactivation modes discerned in this study are conferred by two states of Na channel the interconversion of which are regulated by an as yet unknown mechanism that seems to involve cytosolic factors.

Key words

Sodium channel Oocyte Patch clamp 


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  1. 1.
    Alzheimer C, Schwindt PC, Crill WE (1993) Modal gating of Na Channels as a mechanism of persistent Na Current in pyramidal neurons from rat and cat sensorimotor cortex. J Neurosci 13:660–673Google Scholar
  2. 2.
    Armstrong CM, Bezanilla F, Rojas E (1973) Destruction of sodium conductance inactivation in squid axons perfused with pronase. J Gen Physiol 62:375–391Google Scholar
  3. 3.
    Auld VJ, Goldin AL, Krafte DS, Marshall J, Dunn JM, Catterall WA, Lester HA, Davidson N, Dunn RJ (1988) A rat brain Na+ channel α subunit with novel gating properties. Neuron 1:449–461Google Scholar
  4. 4.
    Auld VJ, Goldin AL, Krafte DS, Catterall WA, Lester HA, Davidson N (1990) A neutral amino acid change in segment IIS4 dramatically alters the gating properties of the voltage-dependent sodium channel. Proc Natl Acad Sci USA 87:323–327Google Scholar
  5. 5.
    Cantiello HF, Patenause CR, Ausiello DA (1989) G Protein subunit, alpha i-3, activates a pertussis toxin-sensitive Na+ channel from the epithelial cell line, A6. J. Biol Chem 264:20867–20870Google Scholar
  6. 6.
    Huguenard JR, Hamill OP, Prince DA (1988) Developmental changes in Na+ conductances in rat neocortical neurons: appearance of a slowly inactivating component. J Neurophysiol 59:778–795Google Scholar
  7. 7.
    Isom LL, De Jongh KS, Reber BFX, Offord J, Charbonneau H, Walsh K, Goldin AL, Catterall WA (1992) Primary structure and functional expression of the β1 subunit of the rat brain sodium channel. Science 256:839–842Google Scholar
  8. 8.
    Joho RH, Moormann JR, VanDongen AMJ, Kirsch GE, Silberberg H, Schuster G, Brown AM (1990) Toxin and kinetic profile of rat brain type III sodium channels expressed in Xenopus oocytes. Mol Brain Res 7:105–113Google Scholar
  9. 9.
    Kayano T, Noda M, Flockerzi V, Takahashi H, Numa S (1988) Primary structure of rat brain sodium channel III deduced from the cDNA sequence. FEBS Lett 228:187–194Google Scholar
  10. 10.
    Kim D, Lewis DL, Graziadei L, Neer EJ, Bar-Sagi D, Clapham DE (1989) G-protein βγ-subunits activate the cardiac muscarinic K+ channel via phospholipase A2. Nature 337:557–560Google Scholar
  11. 11.
    Kirsch GE, Brown AM (1989) Kinetic properties of single sodium channels in rat heart and rat brain. J Gen Physiol 93:85–99Google Scholar
  12. 12.
    Krafte DS, Goldin AL, Auld VJ, Dunn RJ, Davidson N, Lester HA (1990) Inactivation of cloned Na channels expressed in Xenopus oocytes. J Gen Physiol 96:689–706Google Scholar
  13. 13.
    Li M, West JW, Lai Y, Scheuer T, Catterall WA (1992) Functional modulation of brain sodium channels by cAMP-dependent phosphorylation. Neuron 8:1151–1159Google Scholar
  14. 14.
    Loughney K, Kreber R, Ganetzky B (1989) Molecular analysis of the para locus, a sodium channel gene in Drosophila. Cell 58:1143–1154Google Scholar
  15. 15.
    McHugh-Sutkowski E, Catterall WA (1990) β1 Subunits of sodium channels. Studies with subunit-specific antibodies. J Biol Chem 265:12393–12399Google Scholar
  16. 16.
    Messner DJ, Catterall WA (1985) The sodium channel from rat brain. Separation and characterization of subunits. J Biol Chem 260:10597–10604Google Scholar
  17. 17.
    Moorman JR, Kirsch GE, VanDongen AMJ, Joho RH, Brown AM (1990) Fast and slow gating of sodium channels encoded by a single mRNA. Neuron 4:243–252Google Scholar
  18. 18.
    Nilius B (1988) Modal gating behavior of cardiac sodium channels in cell-free membrane patches. Biophys J 53:857–862Google Scholar
  19. 19.
    Noda M, Shimizu S, Tanabe T, Takai T, Kayano T, Ikeda T, Takahashi H, Nakayama H, Kanaoka Y, Minamino N, Kangawa K, Matsu H, Raftery M, Hirose S, Inayama H, Hayashida T, Miyata T, Numa S (1984) Primary structure of Electrophorus electricus sodium channel deduced from cDNA sequence. Nature 312:121–127Google Scholar
  20. 20.
    Noda M, Ikeda T, Kayano T, Suzuki H, Takashima H, Kurasaki M, Takahashi H, Nakayama H, Numa S (1986) Existence of distinct sodium channel messenger RNAs in rat brain. Nature 320:188–192Google Scholar
  21. 21.
    Noda M, Ikeda T, Kayano T, Suzuki H, Takashima H, Takahashi H, Kuno M, Numa S (1986) Expression of functional sodium channels from cloned cDNA. Nature 322: 826–828Google Scholar
  22. 22.
    Numann R, Catterall WA, Scheuer T (1991) Functional modulation of brain sodium channels by protein kinase C phosphorylation. Science 254:115–118Google Scholar
  23. 23.
    Patlak B, Ortiz M (1985) Slow currents through single sodium channels of the adult rat heart. J Gen Physiol 86:89–104Google Scholar
  24. 24.
    Patlak B, Ortiz M (1986) Two modes of gating during late Na+ channel currents in frog sartorius muscle. J Gen Physiol 87:305–326Google Scholar
  25. 25.
    Patton DE, Isom LL, Catterall WA, Goldin AL (1993) The sodium channel β1 subunit alters gating properties of a variety of sodium channels expressed in Xenopus oocytes. Biophys J 64: A5Google Scholar
  26. 26.
    Post JM, Weir K, Archer SL, Hume JR (1993) Redox regulation of K+ channels and its relationship to hypoxic pulmonary vasoconstriction. Biophys J 64: A227Google Scholar
  27. 27.
    Ramaswami M, Tanouye M (1989) Two sodium-channel genes in drosophila: implications for channel diversity. Proc Natl Acad Sci USA 86:2079–2082Google Scholar
  28. 28.
    Rogart RB, Cribbs LL, Muglia LK, Kephart DD, Kaiser MW (1989) Molecular cloning of a putative tetrodotoxin-resistant rat heart Na+ channel isoform. Proc Natl Acad Sci USA 86:8170–8174Google Scholar
  29. 29.
    Ruppersberg JP, Stocker M, Pongs O, Heinemann S, Frank R, Koenen M (1991) Regulation of fast inactivation of cloned mammalian IK(A) channels by cysteine oxidation. Nature 352:711–714Google Scholar
  30. 30.
    Salkoff L. Butler A, Wei A, Scavarda N, Giffen K, Ifune C, Goodman R, Mandel G (1987) Genomic organization and deduced amino acid sequence of a putative sodium channel gene in Drosophila. Science 237:744–749Google Scholar
  31. 31.
    Scheuer T, Auld VJ, Boyd S, Offord J, Dunn R (1990) Functional properties of rat brain sodium channels expressed in a somatic cell line. Science 247:854–858Google Scholar
  32. 32.
    Schubert B, VanDongen AMJ, Kirsch GE, Brown AM (1989) β-adrenergic inhibition of cardiac sodium channels by dual G-protein pathways. Science 245:516–519Google Scholar
  33. 33.
    Starkus JG, Rayner MD, Fleig A, Ruben PC (1993) Photodynamic modification of sodium channels by methylene blue: effects on fast and slow inactivation. Biophys J 65:715–726Google Scholar
  34. 34.
    Suzuki H, Beckh S, Kubo H, Yahagi N, Ishida H, Kayano T, Noda M, Numa S (1988) Functional expression of cloned cDNA encoding sodium channel III. FEBS Lett 228:195–200Google Scholar
  35. 35.
    Trimmer JS, Cooperman SS, Tomiko SA, Zhou J, Crean SM, Boyle MB, Kallen RG, Sheng Z, Barchi RL, Sigworth FJ, Goodman RH, Agnew WS, Mandel G (1989) Primary structure and functional expression of a mammalian skeletal muscle sodium channel. Neuron 3:33–49Google Scholar
  36. 36.
    Vassilev PM, Scheuer T, Catterall WA (1989) Identification of an intracellular peptide segment in sodium channel inactivation. Science 241:1658–1661Google Scholar
  37. 37.
    West JW, Scheuer T, Maechler L, Catterall WA (1992) Efficient expression of rat brain type IIA Na+ channel α subunits in a somatic cell line. Neuron 8:59–70Google Scholar
  38. 38.
    Zhou J, Potts JF, Trimmer JS, Agnew WS, Sigworth FJ (1991) Multiple gating modes and the effect of modulating factors on the μI sodium channel. Neuron 7:775–785Google Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • Andrea Fleig
    • 1
  • Peter C. Ruben
    • 2
  • Martin D. Rayner
    • 1
  1. 1.Department of Physiology, John A. Burns School of MedicineUniversity of HawaiiHonoluluUSA
  2. 2.Békésy Laboratory of NeurobiologyUniversity of HawaiiHonoluluUSA

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