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

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Summary

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.

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References

  1. Adrian, R.H., Marshall, M.W. 1977. Sodium currents in mammalian muscle.J. Physiol. (London) 268:223

    Google Scholar 

  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) 184:970

    Google Scholar 

  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. 243:1337

    PubMed  Google Scholar 

  4. Benz, R., Stark, G. 1975. Kinetics of macrotetrolide-induced ion transport across lipid bilayer membranes.Biochim. Biophys. Acta 382:27

    PubMed  Google Scholar 

  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 York

    Google Scholar 

  6. Bowman, B.J., Slayman, C.W. 1977. Characterization of plasma membrane adenosine triphosphatase ofNeurospora crassa.J. Biol. Chem. 252:3357

    PubMed  Google Scholar 

  7. Briggs, G.E. 1962. Membrane potential differences inChara australis.Proc. R. Soc. London B 156:573

    Google Scholar 

  8. Chapman, J.B., Johnson, E.A. 1976 Current-voltage relationships for theoretical electrogenic sodium pump modelsProc. Aust. Physiol. Pharmacol. Soc.7:69P

  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. 22:365

    Google Scholar 

  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, Berlin

    Google Scholar 

  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. 43:321

    Google Scholar 

  12. Cross, S.B., Keynes, R.D., Rybová, R. 1965. The coupling of sodium efflux and potassium influx in frog muscle.J. Physiol. (London) 181:865

    Google Scholar 

  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. 21:558

    Google Scholar 

  14. Dilley, R.A., Giaquinta, R.T. 1975. H+ ion transport and energy transduction in chloroplasts.Curr. Top. Membr. Transp. 7:49

    Google Scholar 

  15. Finkelstein, A. 1964. Carrier model for active transport of ions across a mosaic membrane.Biophys. J. 4:421

    Google Scholar 

  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 York

    Google Scholar 

  17. Gradmann D. 1975. Analog circuit of theAcetabularia membrane.J. Membrane Biol. 25:183

    Google Scholar 

  18. Gradmann D., Slayman, C.L. 1975. Oscillations of an electrogenic pump in the plasma membrane ofNeurospora.J. Membrane Biol. 23:181

    Google Scholar 

  19. Hanstein, W.G. 1976. Uncoupling of oxidative phosphorylation.Biochim. Biophys. Acta 456:129

    PubMed  Google Scholar 

  20. Harold, F.M. 1977. Membranes and energy transduction in bacteria.Curr. Top. Bioenerg. 6:83

    Google Scholar 

  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. 5:187

    PubMed  Google Scholar 

  22. Helman, S.I., Fisher, R.S. 1977. Microelectrode studies of the active Na transport pathway of frog skin.J. Gen. Physiol. 69:571

    PubMed  Google Scholar 

  23. Higinbotham, N. 1973. Electropotentials of plant cells.Annu. Rev. Plant Physiol. 24:25

    Google Scholar 

  24. Hill, A.E. 1967. Ion and water transport inLimonium. II. Short-circuit analysis.Biochim. Biophys. Acta 135:461

    PubMed  Google Scholar 

  25. Hunsley, D., Gooday, G.W. 1974. The structure and development of septa inNeurospora crassa.Protoplasma 82:125

    PubMed  Google Scholar 

  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. 72:1153

    Google Scholar 

  27. Komor, E., Tanner, W. 1974. The hexose-proton cotransport system inChlorella.J. Gen. Physiol. 64:568

    PubMed  Google Scholar 

  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:897

    Google Scholar 

  29. Lambowitz, A.M., Slayman, C.W. 1971. Cyanide-resistant respiration inNeurospora crassa.J. Bacteriol. 108:1087

    PubMed  Google Scholar 

  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. 62:1

    Google Scholar 

  31. Marmor, M.F. 1971. The independence of electrogenic sodium transport and membrane potential in a molluscan neurone.J. Physiol. (London) 218:599

    Google Scholar 

  32. Marquardt, D.W. 1963. An algorithm for least-squares estimation of non-linear parameters.J. Soc. Ind. Appl. Math. 11:431

    Google Scholar 

  33. Mitchell, P. 1963. Molecule, group and electron translocation through natural membranes.Biochem. Soc. Symp. 22:142

    Google Scholar 

  34. Moreton, R.B. 1969. An investigation of the electrogenic sodium pump in snail neurones, using the constant field theory.J. Exp. Biol. 51:181

    PubMed  Google Scholar 

  35. Ramos, S., Kaback, H.R. 1977. The relationship between the electrochemical proton gradient and active transport inEscherichia coli membrane vesicles.Biochemistry 16:854

    PubMed  Google Scholar 

  36. Ritchie, J.M. 1971. Electrogenic ion pumping in nervous tissue.Curr. Top. Bioenerg. 4:327

    Google Scholar 

  37. Scarborough, G.A. 1977. Properties of theNeurospora crassa plasma membrane ATPase.Arch. Biochem. Biophys. 180:384

    PubMed  Google Scholar 

  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, London

    Google Scholar 

  39. Skulachev, V.P. 1977. Transmembrane electrochemical H+-potential as a convertible energy source for the living cell.FEBS Lett. 74:1

    PubMed  Google Scholar 

  40. Slayman, C.L. 1965. Electrical properties ofNeurospora crassa Effects of external cations on the intracellular potential.J. Gen. Physiol. 49:69

    PubMed  Google Scholar 

  41. Slayman, C.L. 1965. Electrical properties ofNeurospora crassa: Respiration and the intracellular potential.J. Gen. Physiol. 49:93

    PubMed  Google Scholar 

  42. Slayman, C.L. 1970. Movement of ions and electrogenesis in microorganisms.Am. Zool. 10:377

    PubMed  Google Scholar 

  43. Slayman, C.L. 1973. Adenine nucleotide levels inNeurospora, as influenced by conditions of growth and by metabolic inhibitors.J. Bacteriol. 114:752

    PubMed  Google Scholar 

  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, Berlin

    Google Scholar 

  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 York

    Google Scholar 

  46. Slayman, C.L., Gradmann D. 1973. The equivalent circuit for a membrane with an electrogenic pump.Abstr. Biophys. Soc. Meeting, Item TAM-J10

  47. Slayman, C.L., Gradmann, D. 1975. Electrogenic proton transport in the plasma membrane ofNeurospora.Biophys. J. 15:968

    PubMed  Google Scholar 

  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, Rome

    Google Scholar 

  49. Slayman, C.L., Long, W.S., Gradmann, D. 1976. “Action potentials” inNeurospora crassa, a mycelial fungus.Biochim. Biophys. Acta 426:732

    PubMed  Google Scholar 

  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. 14:305

    Google Scholar 

  51. Slayman, C.L., Lu, C.Y.-H., Shane, L. 1970. Correlated changes in membrane potential and ATP concentrations inNeurospora.Nature (London) 226:274

    Google Scholar 

  52. Slayman, C.L., Slayman, C.W. 1968. Net uptake of potassium inNeurospora: Exchange for sodium and hydrogen ions.J. Gen. Physiol. 52:424

    PubMed  Google Scholar 

  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 71:1935

    PubMed  Google Scholar 

  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. 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. 250:396

    PubMed  Google Scholar 

  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, Berlin

    Google Scholar 

  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 288:73

    PubMed  Google Scholar 

  58. Stark, G. 1973. Rectification phenomena in carrier-mediated ion transport.Biochim. Biophys. Acta 298:323

    PubMed  Google Scholar 

  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. 5:133

    Google Scholar 

  60. Thayer, W.S., Hinkle, P.C. 1973. Stoichiometry of adenosine triphosphate-driven proton translocation in bovine heart submitochondrial particles.J. Biol. Chem. 248:5395

    PubMed  Google Scholar 

  61. Thomas, R.C. 1969. Membrane current and intracellular sodium changes in a snail neurone during extrusion of injected sodium.J. Physiol. (London) 201:495

    Google Scholar 

  62. Thomas, R.C. 1972. Electrogenic sodium pump in nerve and muscle cells.Physiol. Rev. 52:563

    PubMed  Google Scholar 

  63. Trinci, A.P.J., Collinge, A.J. 1974. Occlusion of the septal pores of damaged hyphae ofNeurospora crassa by hexagonal crystals.Protoplasma 80:57

    PubMed  Google Scholar 

  64. Tsuda, S., Tatum, E.L. 1961. Intracellular crystalline ergosterol inNeurospora.J. Biophys. Biochem. Cytol. 11:171

    PubMed  Google Scholar 

  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. 23:100

    Google Scholar 

  66. Vogel, H.J. 1956. A convenient growth medium forNeurospora (Medium N).Microbial Gen. Bull. 13:42

    Google Scholar 

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Author notes

  1. Dietrich Gradmann

    Present address: Institut für Biologie, Universität Tübingen, 7400, Tübingen, F.R.G.

  2. Ulf-Peter Hansen

    Present address: Institut für Angewandte Physik, Universität Kiel, 2300, Kiel, F.R.G.

Authors and Affiliations

  1. Department of Physiology, Yale School of Medicine, 06510, New Haven, Conn

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

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Gradmann, D., Hansen, UP., Long, W.S. et al. Current-voltage relationships for the plasma membrane and its principal electrogenic pump inNeurospora crassa: I. Steady-state conditions. J. Membrain Biol. 39, 333–367 (1978). https://doi.org/10.1007/BF01869898

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