Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

External Na dependence of ouabain-sensitive ATP: ADP exchange initiated by photolysis of intracellular caged-ATP in human red cell ghosts

Abstract

Coupled active transport of Na+ and K+ across cellular plasma membranes is mediated by (Na+ + K+)-stimulated Mg2+-dependent ATPase. Active cation transport by this Na pump involves a cyclic Na-dependent phosphorylation of the enzyme by intracellular ATP and hydrolytic dephosphorylation of the phosphoenzyme, stimulated by K+ (ref. 1). In human red blood cells2, skeletal muscle23 and squid axons3,4, replacement of extracellular K by Na results in a ouabain-sensitive efflux of Na coupled to an influx of extracellular Na. There is apparently no net Na movement5 nor net hydrolysis of ATP6. The rate of Na:Na exchange is stimulated by increased levels of ADP7 and exchange transport is not observed in cells totally depleted of intracellular ATP8. These characteristics suggest that the biochemical mechanism underlying the Na exchange mode of the Na pump involves phosphorylation of the enzyme by ATP (which requires intracellular Na) followed by its dephosphorylation by ADP. Such a reaction has been observed in partially purified (Na+ + K+) ATPase from a variety of sources9–11 and its dependence on Na concentration has been described12,13 (although not previously for the red cell enzyme). In the present work, intracellular ATP:ADP exchange reaction was initiated by photoreleased ATP following brief irradiation at 350 nm of ghosts containing caged-ATP14. The ouabain-sensitive component of the ensuing ATP: ADP exchange reaction shows a biphasic response to extracellular Na. External Na in the range 0–10 mM has an inhibitory effect whilst increasing concentrations beyond this range stimulate the rate of exchange in a roughly linear fashion up to 100 mM Na. These results represent the first direct demonstration of the sidedness of the effects of Na on this partial sequence in the overall enzyme cycle and bear a qualitative resemblance to the Na effects on the Na-ATPase which occur in the absence of intracellular ADP in human red blood cells15.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Glynn, I. M. & Karlish, S. J. D. A. Rev. Physiol. 37, 13–55 (1975).

    Article  CAS  Google Scholar 

  2. Garrahan, P. J. & Glynn, I. M. J. Physiol., Lond. 192, 189–216 (1967).

    Article  CAS  Google Scholar 

  3. Kennedy, B. G. & DeWeer, P. J. gen. Physiol. 68, 405–420 (1976).

    Article  CAS  Google Scholar 

  4. DeWeer, P. Nature 219, 730–731 (1968); 226, 1251–1252 (1970).

    Article  ADS  CAS  Google Scholar 

  5. Garrahan, P. J. & Glynn, I. M. J. Physiol., Lond. 192, 159–174 (1967).

    Article  CAS  Google Scholar 

  6. Garrahan, P. J. & Glynn, I. M. J. Physiol., Lond. 192, 217–235 (1967).

    Article  CAS  Google Scholar 

  7. Glynn, I. M. & Hoffman, J. F. J. Physiol., Lond. 218, 239–256 (1971).

    Article  CAS  Google Scholar 

  8. Cavieres, J. D. & Glynn, I. M. J. Physiol., Lond. 297, 637–645 (1979).

    Article  CAS  Google Scholar 

  9. Fahn, S., Koval, G. J. & Albers, R. W. J. biol. Chem. 241, 1882–1889 (1966).

    CAS  PubMed  Google Scholar 

  10. Stahl, W. L. J. Neurochem. 15, 499–509; 511–518 (1968).

    Article  CAS  Google Scholar 

  11. Banerjee, S. P. & Wong, S. M. E. J. biol. Chem. 247, 5409–5413 (1972).

    CAS  PubMed  Google Scholar 

  12. Wildes, R. A., Evans, H. J. & Chiu, J. Biochim. biophys. Acta 307, 162–168 (1973).

    Article  CAS  Google Scholar 

  13. Beauge, L. A. & Glynn, I. M. J. Physiol., Lond. 289, 17–31 (1979).

    Article  CAS  Google Scholar 

  14. Kaplan, J. H., Forbush III, B. & Hoffman, J. F. Biochemistry 17, 1929–1935 (1978).

    Article  CAS  Google Scholar 

  15. Glynn, I. M. & Karlish, S. J. D. J. Physiol., Lond. 256, 465–496 (1976).

    Article  CAS  Google Scholar 

  16. Lienhard, G. E. & Secemski, I. I. J. biol. Chem. 248, 1121–1123 (1973).

    CAS  PubMed  Google Scholar 

  17. Wood, P. G. Fedn. Proc. 34, 249 (1975).

    Google Scholar 

  18. Parks, R. E. Jr. & Agarwal, R. P. Enzymes 8, 307–333 (1973).

    Article  CAS  Google Scholar 

  19. Stellwagen, E. C. Acct. Chem. Res. 10, 92–98 (1977).

    Article  CAS  Google Scholar 

  20. Kimmich, G. A., Randles, J. & Brand, J. S. Analyt. Biochem. 69, 187–209 (1975).

    Article  CAS  Google Scholar 

  21. Fairbanks, G., Steck, T. L. & Wallach, D. F. H. Biochemistry 10, 2606–2616 (1971).

    Article  CAS  Google Scholar 

  22. Jennings, M. L. & Passow, H. Biochim. biophys. Acta 554, 498–519 (1979).

    Article  CAS  Google Scholar 

  23. Caldwell, P. C., Hodgkin, A. L., Keynes, R. D. & Shaw, T. I. J. Physiol., Lond. 152, 561–690 (1960).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kaplan, J., Hollis, R. External Na dependence of ouabain-sensitive ATP: ADP exchange initiated by photolysis of intracellular caged-ATP in human red cell ghosts. Nature 288, 587–589 (1980). https://doi.org/10.1038/288587a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/288587a0

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing