The Journal of Membrane Biology

, Volume 39, Issue 4, pp 333–367 | Cite as

Current-voltage relationships for the plasma membrane and its principal electrogenic pump inNeurospora crassa: I. Steady-state conditions

  • Dietrich Gradmann
  • Ulf-Peter Hansen
  • W. Scott Long
  • Clifford L. Slayman
  • Jens Warncke


The nonlinear membrane current-voltage relationship (I–V curve) for intact hyphae ofNeurospora crassa has been determined by means of a 3-electrode voltage-clamp technique, plus “quasi-linear” cable theory. Under normal conditions of growth and respiration, the membraneI–V curve is best described as a parabolic segement convex in the direction of depolarizing current. At the average resting potential of −174 mV, the membrane conductance is ≈190 μmhos/cm2; conductance increases to ≈240 μmhos/cm2 at −300 mV, and decreases to ≈130 μmhos/cm2 at 0 mV. Irreversible membrane breakdown occurs at potentials beyond this range.

Inhibition of the primary electrogenic pump inNeurospora by ATP withdrawal (with 1mm KCN) depolarizes the membrane to the range of −40 to −70 mV and reduces the slope of theI–V curve by a fixed scaling factor of approximately 0.8. For wild-typeNeurospora, compared under control conditions and during steady-state inhibition by cyanide, theI–V difference curve — presumed to define the current-voltage curve for the electrogenic pump — is a saturation function with maximal current of ≈20 μA/cm2, a half-saturation potential near −300 mV, and a projected reversal potential of ca. −400 mV. This value is close to the maximal free energy available to the pump from ATP hydrolysis, so that pump stoichiometry must be close to 1 H+ extruded:1 ATP split.

The time-courses of change in membrane potential and resistance with cyanide are compatible with the steady-stateI–V curves, under the assumption that cyanide has no major effects other than ATP withdrawal. Other inhibitors, uncouplers, and lowered temperature all have more complicated effects.

The detailed temporal analysis of voltage-clamp data showed three time-constants in the clamping currents: one of 10 msec, for charging the membrane capacitance (0.9 μF/cm2) a second of 50–75 msec; and a third of 20–30 sec, perhaps representing changes of intracellular composition.


Versus Curve Electrogenic Pump Cable Theory Parabolic Segement Nonlinear Membrane 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Adrian, R.H., Marshall, M.W. 1977. Sodium currents in mammalian muscle.J. Physiol. (London) 268:223Google Scholar
  2. 2.
    Adrian, R.H., Slayman, C.L. 1966. Membrane potential and conductance during transport of sodium, potassium, and rubidium in frog muscle.J. Physiol (London) 184:970Google Scholar
  3. 3.
    Alberty, R.A. 1968. Effect of pH and metal ion concentration on the equilibrium hydrolysis of adenosine triphosphate to adenosine diphosphate.J. Biol. Chem. 243:1337PubMedGoogle Scholar
  4. 4.
    Benz, R., Stark, G. 1975. Kinetics of macrotetrolide-induced ion transport across lipid bilayer membranes.Biochim. Biophys. Acta 382:27PubMedGoogle Scholar
  5. 5.
    Blankemeyer, J.T., Harvey, W.R. 1977. Insect midgut as a model epithelium.In: Water Relations in Membrane Transport in Plants and Animals. A.M. Jungreis, T.K. Hodges, A. Kleinzeller, and S.G. Schultz, editors. pp. 161–182 Academic Press, New YorkGoogle Scholar
  6. 6.
    Bowman, B.J., Slayman, C.W. 1977. Characterization of plasma membrane adenosine triphosphatase ofNeurospora crassa.J. Biol. Chem. 252:3357PubMedGoogle Scholar
  7. 7.
    Briggs, G.E. 1962. Membrane potential differences inChara australis.Proc. R. Soc. London B 156:573Google Scholar
  8. 8.
    Chapman, J.B., Johnson, E.A. 1976 Current-voltage relationships for theoretical electrogenic sodium pump modelsProc. Aust. Physiol. Pharmacol. Soc.7:69PGoogle Scholar
  9. 9.
    Coster, H.G.L. 1969. The role of pH in the punch-through effect in the electrical characteristics ofChara australis.Aust. J. Biol. Sci. 22:365Google Scholar
  10. 10.
    Coster, H.G.L., Smith, J.R. 1974. The effect of pH on the low frequency capacitance of the membranes ofChara corallina.In: Membrane Transport in Plants. U. Zimmermann and J. Dainty, editors. pp. 154–161. Springer-Verlag, BerlinGoogle Scholar
  11. 11.
    Crane, E.E., Davies, R.E., Longmuir, N.M. 1948. Relations between hydrochloric acid secretion and electrical phenomena in frog gastric mucosa.Biochem. J. 43:321Google Scholar
  12. 12.
    Cross, S.B., Keynes, R.D., Rybová, R. 1965. The coupling of sodium efflux and potassium influx in frog muscle.J. Physiol. (London) 181:865Google Scholar
  13. 13.
    Dainty, J., Lannoye, R.J., Tarr, S.E. 1970. Voltage-current characteristics ofChara australis during changes of pH and exchange of Ca−Mg in external medium.J. Exp. Bot. 21:558Google Scholar
  14. 14.
    Dilley, R.A., Giaquinta, R.T. 1975. H+ ion transport and energy transduction in chloroplasts.Curr. Top. Membr. Transp. 7:49Google Scholar
  15. 15.
    Finkelstein, A. 1964. Carrier model for active transport of ions across a mosaic membrane.Biophys. J. 4:421Google Scholar
  16. 16.
    Forte, J.G. 1971. Hydrochloric acid secretion by gastric mucosa.In: Membranes and Ion Transport. E.E. Bittar, editor. Vol. 3, p. 111, Wiley Interscience New YorkGoogle Scholar
  17. 17.
    Gradmann D. 1975. Analog circuit of theAcetabularia membrane.J. Membrane Biol. 25:183Google Scholar
  18. 18.
    Gradmann D., Slayman, C.L. 1975. Oscillations of an electrogenic pump in the plasma membrane ofNeurospora.J. Membrane Biol. 23:181Google Scholar
  19. 19.
    Hanstein, W.G. 1976. Uncoupling of oxidative phosphorylation.Biochim. Biophys. Acta 456:129PubMedGoogle Scholar
  20. 20.
    Harold, F.M. 1977. Membranes and energy transduction in bacteria.Curr. Top. Bioenerg. 6:83Google Scholar
  21. 21.
    Haydon, D.A., Hladky, S.B. 1972. Ion transport across thin lipid membranes: A critical discussion of mechanisms in selected systems.Q. Rev. Biophys. 5:187PubMedGoogle Scholar
  22. 22.
    Helman, S.I., Fisher, R.S. 1977. Microelectrode studies of the active Na transport pathway of frog skin.J. Gen. Physiol. 69:571PubMedGoogle Scholar
  23. 23.
    Higinbotham, N. 1973. Electropotentials of plant cells.Annu. Rev. Plant Physiol. 24:25Google Scholar
  24. 24.
    Hill, A.E. 1967. Ion and water transport inLimonium. II. Short-circuit analysis.Biochim. Biophys. Acta 135:461PubMedGoogle Scholar
  25. 25.
    Hunsley, D., Gooday, G.W. 1974. The structure and development of septa inNeurospora crassa.Protoplasma 82:125PubMedGoogle Scholar
  26. 26.
    Kayalar, C., Rosing, J., Boyer, P.D. 1976. 2,4-Dinitrophenol causes a marked increase in the apparentK m ofP i and ADP for oxidative phosphorylation.Biochim. Biophys. Res. Commun. 72:1153Google Scholar
  27. 27.
    Komor, E., Tanner, W. 1974. The hexose-proton cotransport system inChlorella.J. Gen. Physiol. 64:568PubMedGoogle Scholar
  28. 28.
    Lambert, J.D.C., Kerkut, G.A., Walker, R.J. 1974. The electrogenic sodium pump and membrane potential of identified neurons inHelix aspersa.Comp. Biochem. Physiol. 47A:897Google Scholar
  29. 29.
    Lambowitz, A.M., Slayman, C.W. 1971. Cyanide-resistant respiration inNeurospora crassa.J. Bacteriol. 108:1087PubMedGoogle Scholar
  30. 30.
    Mandel, L.J., Curran, P.F. 1973. Response of the frog skin to steady-state voltage clamping. II. The active pathway.J. Gen. Physiol. 62:1Google Scholar
  31. 31.
    Marmor, M.F. 1971. The independence of electrogenic sodium transport and membrane potential in a molluscan neurone.J. Physiol. (London) 218:599Google Scholar
  32. 32.
    Marquardt, D.W. 1963. An algorithm for least-squares estimation of non-linear parameters.J. Soc. Ind. Appl. Math. 11:431Google Scholar
  33. 33.
    Mitchell, P. 1963. Molecule, group and electron translocation through natural membranes.Biochem. Soc. Symp. 22:142Google Scholar
  34. 34.
    Moreton, R.B. 1969. An investigation of the electrogenic sodium pump in snail neurones, using the constant field theory.J. Exp. Biol. 51:181PubMedGoogle Scholar
  35. 35.
    Ramos, S., Kaback, H.R. 1977. The relationship between the electrochemical proton gradient and active transport inEscherichia coli membrane vesicles.Biochemistry 16:854PubMedGoogle Scholar
  36. 36.
    Ritchie, J.M. 1971. Electrogenic ion pumping in nervous tissue.Curr. Top. Bioenerg. 4:327Google Scholar
  37. 37.
    Scarborough, G.A. 1977. Properties of theNeurospora crassa plasma membrane ATPase.Arch. Biochem. Biophys. 180:384PubMedGoogle Scholar
  38. 38.
    Skulachev, V.P. 1974. Mitochondrial adenosine triphosphatase, cytochromec oxidase, and bacteriorhodopsin as biological electric generators.In: Membrane Adenosine Triphosphatases and Transport Processes. J.R. Bronk, editor. p. 175. Biochemical Society, LondonGoogle Scholar
  39. 39.
    Skulachev, V.P. 1977. Transmembrane electrochemical H+-potential as a convertible energy source for the living cell.FEBS Lett. 74:1PubMedGoogle Scholar
  40. 40.
    Slayman, C.L. 1965. Electrical properties ofNeurospora crassa Effects of external cations on the intracellular potential.J. Gen. Physiol. 49:69PubMedGoogle Scholar
  41. 41.
    Slayman, C.L. 1965. Electrical properties ofNeurospora crassa: Respiration and the intracellular potential.J. Gen. Physiol. 49:93PubMedGoogle Scholar
  42. 42.
    Slayman, C.L. 1970. Movement of ions and electrogenesis in microorganisms.Am. Zool. 10:377PubMedGoogle Scholar
  43. 43.
    Slayman, C.L. 1973. Adenine nucleotide levels inNeurospora, as influenced by conditions of growth and by metabolic inhibitors.J. Bacteriol. 114:752PubMedGoogle Scholar
  44. 44.
    Slayman, C.L. 1974. Proton pumping and generalized energetics of transport: A review.In: Membrane Transport in Plants. U. Zimmermann and J. Dainty, editors. p. 107. Springer-Verlag, BerlinGoogle Scholar
  45. 45.
    Slayman, C.L. 1977. Energetics and control of transport inNeurospora.In: Water Relations in Membrane Transport in Plants and Animals. A.M. Jungreis, T.K. Hodges, A. Kleinzeller and S.G. Schultz, editors. p. 69. Academic Press, New YorkGoogle Scholar
  46. 46.
    Slayman, C.L., Gradmann D. 1973. The equivalent circuit for a membrane with an electrogenic pump.Abstr. Biophys. Soc. Meeting, Item TAM-J10Google Scholar
  47. 47.
    Slayman, C.L., Gradmann, D. 1975. Electrogenic proton transport in the plasma membrane ofNeurospora.Biophys. J. 15:968PubMedGoogle Scholar
  48. 48.
    Slayman, C.L., Gradmann, D., Hansen, U.-P. 1976. Electrophysiological aspects of energy transfer in the plasma membrane ofNeurospora.In: Semaine d'Étude sur le Thème Membranes Biologiques et Artificielles et la Désalinisation de l'Eau. R. Passino, editor. p. 403. Pontificial Academy of Sciences, RomeGoogle Scholar
  49. 49.
    Slayman, C.L., Long, W.S., Gradmann, D. 1976. “Action potentials” inNeurospora crassa, a mycelial fungus.Biochim. Biophys. Acta 426:732PubMedGoogle Scholar
  50. 50.
    Slayman, C.L., Long, W.S., Lu, C.Y.-H. 1973. The relationship between ATP and an electrogenic pump in the plasma membrane ofNeurospora crassa.J. Membrane Biol. 14:305Google Scholar
  51. 51.
    Slayman, C.L., Lu, C.Y.-H., Shane, L. 1970. Correlated changes in membrane potential and ATP concentrations inNeurospora.Nature (London) 226:274Google Scholar
  52. 52.
    Slayman, C.L., Slayman, C.W. 1968. Net uptake of potassium inNeurospora: Exchange for sodium and hydrogen ions.J. Gen. Physiol. 52:424PubMedGoogle Scholar
  53. 53.
    Slayman, C.L., Slayman, C.W. 1974. Depolarization of the plasma membrane ofNeurospora during active transport of glucose: Evidence for a proton-dependent cotransport system.Proc. Nat. Acad. Sci. USA 71:1935PubMedGoogle Scholar
  54. 54.
    Slayman, C.L., Slayman, C.W., Hansen, U.-P. 1977. Current-voltage relationships for the glucose/H+ cotransport system inNeurospora.In: Transmembrane Ionic Exchanges in Plants. M. Thellier and A. Monnier, editors. C.N.R.S., Paris (in press)Google Scholar
  55. 55.
    Slayman, C.W., Rees, D.C., Orchard, P.P., Slayman, C.L. 1975. Generation of adenosine triphosphate in cytochrome-deficient mutants ofNeurospora.J. Biol. Chem. 250:396PubMedGoogle Scholar
  56. 56.
    Slayman, C.W., Slayman, C.L. 1975. Energy coupling in the plasma membrane ofNeurospora: ATP-dependent proton transport and proton-dependent sugar cotransport.In: Molecular Aspects of Membrane Phenomena. H.R. Kaback, H. Neurath, G.K. Radda, R. Schwyzer, and W.R. Wiley, editors. p. 233. Springer-Verlag, BerlinGoogle Scholar
  57. 57.
    Spanswick, R.M. 1972. Evidence for an electrogenic ion pump inNitella translucens. I. The effects of pH, K+ Na+, light and temperature on the membrane potential and resistance.Biochim. Biophys. Acta 288:73PubMedGoogle Scholar
  58. 58.
    Stark, G. 1973. Rectification phenomena in carrier-mediated ion transport.Biochim. Biophys. Acta 298:323PubMedGoogle Scholar
  59. 59.
    Stark, G., Benz, R. 1971. The transport of potassium through lipid bilayer membranes by the neutral carriers valinomycin and monactin. Experimental studies to a previously proposed model.J. Membrane Biol. 5:133Google Scholar
  60. 60.
    Thayer, W.S., Hinkle, P.C. 1973. Stoichiometry of adenosine triphosphate-driven proton translocation in bovine heart submitochondrial particles.J. Biol. Chem. 248:5395PubMedGoogle Scholar
  61. 61.
    Thomas, R.C. 1969. Membrane current and intracellular sodium changes in a snail neurone during extrusion of injected sodium.J. Physiol. (London) 201:495Google Scholar
  62. 62.
    Thomas, R.C. 1972. Electrogenic sodium pump in nerve and muscle cells.Physiol. Rev. 52:563PubMedGoogle Scholar
  63. 63.
    Trinci, A.P.J., Collinge, A.J. 1974. Occlusion of the septal pores of damaged hyphae ofNeurospora crassa by hexagonal crystals.Protoplasma 80:57PubMedGoogle Scholar
  64. 64.
    Tsuda, S., Tatum, E.L. 1961. Intracellular crystalline ergosterol inNeurospora.J. Biophys. Biochem. Cytol. 11:171PubMedGoogle Scholar
  65. 65.
    Ussing, H.H., Zerahn, K. 1951. Active transport of sodium as the source of electric current in the short-circuited isolated frog skin.Acta Physiol. Scand. 23:100Google Scholar
  66. 66.
    Vogel, H.J. 1956. A convenient growth medium forNeurospora (Medium N).Microbial Gen. Bull. 13:42Google Scholar

Copyright information

© Springer-Verlag New York Inc. 1978

Authors and Affiliations

  • Dietrich Gradmann
    • 1
  • Ulf-Peter Hansen
    • 1
  • W. Scott Long
    • 1
  • Clifford L. Slayman
    • 1
  • Jens Warncke
    • 1
  1. 1.Department of PhysiologyYale School of MedicineNew Haven

Personalised recommendations