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Analog circuit of theAcetabularia membrane

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Summary

The high membrane potential ofAcetabularia (E m=−170 mV) is due to an electrogenic pump in parallel with the passive diffusion system (E d=−80 mV) which could be studied separately in the cold, when the pump is blocked. Electrical measurements under normal conditions show that the pump pathway consists of its electromotive forceE p with two elementsP 1 andP 2 in series;P 2 is shunted by a large capacitance (C p=3 mF cm−2). The nonlinear current-voltage relationship ofP 1 (light- and temperature-sensitive) could be determined separately; it reflects the properties of a carrier-mediated electrogenic pump. The value ofE p (−190 mV) indicates a stoichiometry of 2∶1 between electrogenically transported charges and ATP. The electrical energy, normally stored inC p, compares well with the metabolic energy, stored in the ATP pool. The nonlinear current-voltage relationship ofP 2 (attributed to phosphorylating reactions) is also sensitive to light and temperature and is responsible for the region of negative conductance of the overall current-voltage relationship. The power of the pump (1 μW cm−2) amounts to some percent of the total energy turnover. The high Cl fluxes (1 nmol cm−2 sec−1) and the electrical properties of the plasmalemma are not as closely related as assumed previously. For kinetic reasons, a direct and specific Cl pathway between the vacuole and outside is postulated to exist.

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References

  1. Adrian, R. H., Chandler, W. K., Hodgkin, A. L. 1970. Voltage clamp experiments in striated muscle fibres.J. Physiol. 208: 607

    PubMed  Google Scholar 

  2. Barry, P. H., Hope, A. B. 1969a. Electroosmosis in membranes: Effects of unstirred layers and transport numbers. I. Theory.Biophys. J. 9: 700

    PubMed  Google Scholar 

  3. Barry, P. H., Hope, A. B. 1969b. Electroosmosis in membranes: Effects of unstirred layers and transport numbers. II. Experimental.Biophys. J. 9: 729

    PubMed  Google Scholar 

  4. Beth, K. 1953. Experimentelle Untersuchungen über die Wirkung des Lichtes auf die Formbildung von kernhaltigen und kernlosenAcetabularia-Zellen.Z. Naturforsch. 8b: 334

    Google Scholar 

  5. Brändle, E. P. O., Kötter, R., Zetsche, K. 1975. Changes of pH in culture solution ofAcetabularia caused by proton flux.Protoplasma 83: 173

    Google Scholar 

  6. Cole, K. S. 1961. Non-linear current-potential relations in an axon membrane.J. Gen. Physiol. 44: 1055

    PubMed  Google Scholar 

  7. Cram, W. J. 1968. Compartmentation and exchange of chloride in carrot root tissue.Biochim. Biophys. Acta 163: 339

    PubMed  Google Scholar 

  8. Findlay, G. P., Hope, A. B., Pitman, M. G., Smith, F. A., Walker, N. A. 1971. Ionic relations of marine algae. III.Chaetomorpha: Membrane electrical properties and chloride fluxes.Aust. J. Biol. Sci. 24: 731

    Google Scholar 

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

    Google Scholar 

  10. Gläsel, R. M., Zetsche, K. 1975.36Chloride fluxes ofAcetabularia.Protoplasma 83: 175

    Google Scholar 

  11. Gradmann, D. 1970. Einfluss von Licht, Temperatur und Aussenmedium auf das elektrische Verhalten vonAcetabularia.Planta 93: 323

    Article  Google Scholar 

  12. Gradmann, D. 1974. Wirkung des Lichts auf die elektrogene Pumpe vonAcetabularia. Zusammenfassungen der Vorträge zur Tagung der Deutschen Botanischen Gesellschaft, Würzburg:70

  13. Gradmann, D., Bentrup, F. W. 1970. Light-induced membrane potential changes and rectification inAcetabularia.Naturwissenschaften 57: 46

    Google Scholar 

  14. Gradmann D., Bokeloh, G. 1975. Energy consumption of the electrogenic pump inAcetabularia mediterranea.Protoplasma 83: 172

    Google Scholar 

  15. Gradmann, D., Klemke, W. 1974. Current-voltage relationship of the electrogenic pump inAcetabularia.In: Membrane Transport in Plants. U. Zimmermann and J. Dainty, editors. p. 131. Springer-Verlag, Berlin-Heidelberg-New York

    Google Scholar 

  16. Gradmann, D., Wagner, G., Gläsel, R. M. 1973. Chloride efflux during light-triggered action potentials inAcetabularia mediterranea.Biochim. Biophys. Acta 323: 151

    PubMed  Google Scholar 

  17. Hämmerling, J. 1944. Zur Lebensweise, Fortpflanzung und Entwicklung verschiedener Dasycladaceen.Arch. Protistenk. 97: 7

    Google Scholar 

  18. Hogg, J., Williams, E. J., Johnston, R. J. 1968. A simplified method for measuring membrane resistances inNitella translucens.Biochim. Biophys. Acta 150: 518

    PubMed  Google Scholar 

  19. Hogg, J., Williams, E. J., Johnston, R. J. 1969. The membrane electrical parameters ofNitella translucens.J. Theoret. Biol. 24: 317

    Google Scholar 

  20. Lilley, R. McC., Hope, A. B. 1971. Chloride transport and photosynthesis in cells ofGriffithsia.Biochim. Biophys. Acta 226: 161

    PubMed  Google Scholar 

  21. MacRobbie, E. A. C. 1969. Ion fluxes to the vacuole ofNitella translucens.J. Exp. Bot. 20: 236

    Google Scholar 

  22. Mergenhagen, D., Schweiger, H. G. 1974. Circadian rhythmicity: Does intercellular synchronization occur inAcetabularia?Plant Sci. Lett. 3: 387

    Google Scholar 

  23. Mitchell, P. 1961. Coupling of phosphorylation to electron and hydrogen transfer by a chemiosmotic type of mechanism.Nature 191: 144

    PubMed  Google Scholar 

  24. Mummert, H., Gradmann, D. 1976. Correlation of potassium fluxes and electrical properties of the membrane ofAcetabularia. (In preparation)

  25. Saddler, H. D. W. 1970a. The ionic relations ofAcetabularia mediterranea J. Exp. Bot. 21: 345

    Google Scholar 

  26. Saddler, H. D. W. 1970b. The membrane potential ofAcetabularia mediterranea.J. Gen. Physiol. 55: 802

    PubMed  Google Scholar 

  27. Saddler, H. D. W. 1971. Spontaneous and induced changes in the membrane potential and resistance ofAcetabularia mediterranea.J. Membrane Biol. 5: 250

    Google Scholar 

  28. Schilde, C. 1966. Zur Wirkung des Lichtes auf das Ruhepotential der grünen Pflanzenzelle.Planta 71: 184

    Google Scholar 

  29. Schilde, C. 1968. Schnelle photoelektrische Effekte der AlgeAcetabularia.Z. Naturforsch. 23b: 1369

    Google Scholar 

  30. 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 

  31. 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 

  32. Strehler, B. L. 1970. Adenosin-5-triphosphat und Creatinphosphat Bestimmung mit Luciferase.In: Bergmeyer, Methoden der Enzymatischen Analyse. U. H. Bergmeyer, editor. Vol. 2, p. 2036. Verlag Chemie, Weinheim/Bergstrasse

    Google Scholar 

  33. Walker, N. A., Smith, F. A. 1975. Intracellular pH inChara corallina measured by DMO distribution.Plant Sci. Lett. 4: 125

    Article  Google Scholar 

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Gradmann, D. Analog circuit of theAcetabularia membrane. J. Membrain Biol. 25, 183–208 (1975). https://doi.org/10.1007/BF01868574

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  • DOI: https://doi.org/10.1007/BF01868574

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