Advertisement

Two sets of amino acids of the domain I of Cav2.3 Ca2+ channels contribute to their high sensitivity to extracellular protons

  • Thierry CensEmail author
  • Matthieu Rousset
  • Pierre Charnet
Ion Channels, Receptors and Transporters

Abstract

Extracellular acidification decreases Ca2+ current amplitude and produces a depolarizing shift in the activation potential (Va) of voltage-gated Ca2+ channels (VGCC). These effects are common to all VGCC, but differences exist between Ca2+ channel types and the underlying molecular mechanisms remain largely unknown. We report here that the changes in current amplitude induced by extracellular acidification or alkalinisation are more important for Cav2.3 R type than for Cav2.1 P/Q-type Ca2+ channels. This difference results from a higher shift of Va combined with a modification of channel conductance. Although involved in the sensitivity of channel conductance to extracellular protons, neither the EEEE locus nor the divalent cation selectivity locus could explain the specificity of the pH effects. We show that this specificity involves two separate sets of amino acids within domain I of the Cavα subunit. Residues of the voltage sensor domain and residues in the pore domain mediate the effects of extracellular protons on Va and on channel conductance, respectively. These new insights are important for elucidating the molecular mechanisms that control VGCC gating and conductance and for understanding the role of extracellular protons in other channels or membrane-tethered enzymes with similar pore and/or voltage sensor domains.

Keywords

Voltage-gated Ca2+ channels Extracellular pH Conductance Gating 

Abbreviations

VGCC

Voltage-gated Ca2+ channels

HVA

High voltage activated

LVA

Low voltage activated

DCS

Divalent cations selectivity

Va

Activation potential

VSD

Voltage sensor domain

pHo

Extracellular pH

G

Maximal whole cell conductance

Notes

Acknowledgments

This work was supported by the “Centre Nationale de la Recherche Scientifique”, the “Institut Nationale de la Santé Et de la Recherche Médicale”, the “Fondation Simone & Cino Del Duca”, the “Fondation pour la Recherche sur le Cerveau”. We thank T. Snutch and E. Perez-Reyes for kindly providing calcium channels cDNAs, J-M. Donnay and J-C Mazur for oocyte preparations.

References

  1. 1.
    Bezanilla F (2008) How membrane proteins sense voltage. Nat Rev Mol Cell Biol 9:323–332PubMedCrossRefGoogle Scholar
  2. 2.
    Carlin KP (2005) Modulation of calcium currents in mouse ventral horn neurons by extracellular pH. Eur J Neurosci 22:2655–2660PubMedCrossRefGoogle Scholar
  3. 3.
    Catterall WA (1998) Structure and function of neuronal Ca2+ channels and their role in neurotransmitter release. Cell Calcium 24:307–323PubMedCrossRefGoogle Scholar
  4. 4.
    Cens T, Dalle C, Charnet P (1998) Expression of beta subunit modulates surface potential sensing by calcium channels. Pflugers Arch 435:865–867PubMedCrossRefGoogle Scholar
  5. 5.
    Cens T, Leyris JP, Charnet P (2008) Introduction into Ca(v)2.1 of the homologous mutation of Ca(v)1.2 causing the Timothy syndrome questions the role of V421 in the phenotypic definition of P-type Ca(2+) channel. Pflugers Arch 457:417–430PubMedCrossRefGoogle Scholar
  6. 6.
    Cens T, Mangoni ME, Nargeot J, Charnet P (1996) Modulation of the alpha 1A Ca2+ channel by beta subunits at physiological Ca2+ concentration. FEBS Lett 391:232–237PubMedCrossRefGoogle Scholar
  7. 7.
    Cens T, Restituito S, Rousset M, Charnet P (2005) Role of β subunits in voltage-gated calcium channel functions. In: Zamponi GW (ed) Voltage gated calcium channels. Landes Bioscience, Georgetown, Texas, USA, pp 95–112CrossRefGoogle Scholar
  8. 8.
    Cens T, Rousset M, Kajava A, Charnet P (2007) Molecular determinant for specific ca/ba selectivity profiles of low and high threshold Ca2+ channels. J Gen Physiol 130:415–425PubMedCrossRefGoogle Scholar
  9. 9.
    Chen XH, Bezprozvanny I, Tsien RW (1996) Molecular basis of proton block of L-type Ca2+ channels. J Gen Physiol 108:363–374PubMedCrossRefGoogle Scholar
  10. 10.
    Cukierman S, Zinkand WC, French RJ, Krueger BK (1988) Effects of membrane surface charge and calcium on the gating of rat brain sodium channels in planar bilayers. J Gen Physiol 92:431–447PubMedCrossRefGoogle Scholar
  11. 11.
    Delisle BP, Satin J (2000) pH modification of human T-type calcium channel gating. Biophys J 78:1895–1905PubMedCrossRefGoogle Scholar
  12. 12.
    Doering CJ, McRory JE (2007) Effects of extracellular pH on neuronal calcium channel activation. Neuroscience 146:1032–1043PubMedCrossRefGoogle Scholar
  13. 13.
    Du J, Xie J, Yue L (2009) Modulation of TRPM2 by acidic pH and the underlying mechanisms for pH sensitivity. J Gen Physiol 134:471–488PubMedCrossRefGoogle Scholar
  14. 14.
    Goodchild SJ, Lamy C, Seutin V, Marrion NV (2009) Inhibition of K(Ca)2.2 and K(Ca)2.3 channel currents by protonation of outer pore histidine residues. J Gen Physiol 134:295–308PubMedCrossRefGoogle Scholar
  15. 15.
    Green WN, Anderson OS (1991) Surface charges and ion channel function. Annu Rev Physiol 53:341–359PubMedCrossRefGoogle Scholar
  16. 16.
    Kang HW, Moon HJ, Joo SH, Lee JH (2007) Histidine residues in the IS3–IS4 loop are critical for nickel-sensitive inhibition of the Cav2.3 calcium channel. FEBS Lett 581:5774–5780PubMedCrossRefGoogle Scholar
  17. 17.
    Kang HW, Park JY, Jeong SW, Kim JA, Moon HJ, Perez-Reyes E, Lee JH (2006) A molecular determinant of nickel inhibition in Cav3.2 T-type calcium channels. J Biol Chem 281:4823–4830PubMedCrossRefGoogle Scholar
  18. 18.
    Kang HW, Vitko I, Lee SS, Perez-Reyes E, Lee JH (2010) Structural determinants of the high affinity extracellular zinc binding site on Cav3.2 T-type calcium channels. J Biol Chem 285:3271–3281PubMedCrossRefGoogle Scholar
  19. 19.
    Khan A, Romantseva L, Lam A, Lipkind G, Fozzard HA (2002) Role of outer ring carboxylates of the rat skeletal muscle sodium channel pore in proton block. J Physiol 543:71–84PubMedCrossRefGoogle Scholar
  20. 20.
    Klockner U, Mikala G, Schwartz A, Varadi G (1996) Molecular studies of the asymmetric pore structure of the human cardiac voltage-dependent Ca2+ channel. J Biol Chem 271:22293–22296PubMedCrossRefGoogle Scholar
  21. 21.
    Li RA, Velez P, Chiamvimonvat N, Tomaselli GF, Marban E (2000) Charged residues between the selectivity filter and S6 segments contribute to the permeation phenotype of the sodium channel. J Gen Physiol 115:81–92PubMedCrossRefGoogle Scholar
  22. 22.
    Pinchenko VO, Kostyuk PG, Kostyuk EP (2005) Influence of external pH on two types of low-voltage-activated calcium currents in primary sensory neurons of rats. Biochim Biophys Acta 1724:1–7PubMedGoogle Scholar
  23. 23.
    Richards KS, Swensen AM, Lipscombe D, Bommert K (2007) Novel CaV2.1 clone replicates many properties of Purkinje cell CaV2.1 current. Eur J Neurosci 26:2950–2961PubMedCrossRefGoogle Scholar
  24. 24.
    Sather WA, McCleskey EW (2003) Permeation and selectivity in calcium channels. Annu Rev Physiol 65:133–159PubMedCrossRefGoogle Scholar
  25. 25.
    Shah MJ, Meis S, Munsch T, Pape HC (2001) Modulation by extracellular pH of low- and high-voltage-activated calcium currents of rat thalamic relay neurons. J Neurophysiol 85:1051–1058PubMedGoogle Scholar
  26. 26.
    Smirnov SV, Knock GA, Belevych AE, Aaronson PI (2000) Mechanism of effect of extracellular pH on L-type Ca(2+) channel currents in human mesenteric arterial cells. Am J Physiol Heart Circ Physiol 279:H76–H85PubMedGoogle Scholar
  27. 27.
    Sun YM, Favre I, Schild L, Moczydlowski E (1997) On the structural basis for size-selective permeation of organic cations through the voltage-gated sodium channel: effect of alanine mutations at the DEKA locus on selectivity, inhibition by Ca2+ and H+, and molecular sieving. J Gen Physiol 110:693–715PubMedCrossRefGoogle Scholar
  28. 28.
    Talavera K, Janssens A, Klugbauer N, Droogmans G, Nilius B (2003) Extracellular Ca2+ modulates the effects of protons on gating and conduction properties of the T-type Ca2+ channel alpha1G (CaV3.1). J Gen Physiol 121:511–528PubMedCrossRefGoogle Scholar
  29. 29.
    Tang S, Mikala G, Bahinski A, Yatani A, Varadi G, Schwartz A (1993) Molecular localization of ion selectivity sites within the pore of a human L-type cardiac calcium channel. J Biol Chem 268:13026–13029PubMedGoogle Scholar
  30. 30.
    Tombaugh GC, Somjen GG (1996) Effects of extracellular pH on voltage-gated Na+, K + and Ca2+ currents in isolated rat CA1 neurons. J Physiol 493:719–732PubMedGoogle Scholar
  31. 31.
    Tombola F, Pathak MM, Isacoff EY (2006) How does voltage open an ion channel? Annu Rev Cell Dev Biol 22:23–52PubMedCrossRefGoogle Scholar
  32. 32.
    Vacher H, Mohapatra DP, Trimmer JS (2008) Localization and targeting of voltage-dependent ion channels in mammalian central neurons. Physiol Rev 88:1407–1447PubMedCrossRefGoogle Scholar
  33. 33.
    Xiong ZQ, Stringer JL (2000) Extracellular pH responses in CA1 and the dentate gyrus during electrical stimulation, seizure discharges, and spreading depression. J Neurophysiol 83:3519–3524PubMedGoogle Scholar
  34. 34.
    Yang J, Ellinor PT, Sather WA, Zhang JF, Tsien RW (1993) Molecular determinants of Ca2+ selectivity and ion permeation in L-type Ca2+ channels. Nature 366:158–161PubMedCrossRefGoogle Scholar
  35. 35.
    Zamponi GW, Bourinet E, Snutch TP (1996) Nickel block of a family of neuronal calcium channels: subtype- and subunit-dependent action at multiple sites. J Membr Biol 151:77–90PubMedCrossRefGoogle Scholar
  36. 36.
    Zamponi GW, Snutch TP (1996) Evidence for a specific site for modulation of calcium channel activation by external calcium ions. Pflugers Arch 431:470–472PubMedCrossRefGoogle Scholar
  37. 37.
    Zhou W, Jones SW (1995) Surface charges and calcium channel saturation in bullfrog sympathetic neurons. J Gen Physiol 105:441–462PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Thierry Cens
    • 1
    • 2
    • 3
    Email author
  • Matthieu Rousset
    • 1
    • 2
  • Pierre Charnet
    • 1
    • 2
  1. 1.CRBM CNRS UMR 5237MontpellierFrance
  2. 2.CRBM, UMSFMontpellierFrance
  3. 3.CRBMMontpellierFrance

Personalised recommendations