A protein with kinase and phosphatase activities involved in regulation of tricarboxylic acid cycle


Phosphorylation–dephosphorylation reactions as a form of regulatory control are assuming increasing importance in our understanding of cellular processes. The phosphorylation–dephosphorylation reaction was the first example of covalent modification in control and has been found to be present in almost every type of cellular process including synthesis of cell constituents, metabolic pathways and even gene expression1. It has assumed increasing importance as a result of the finding that some proteins coded for by carcinogenic viruses apparently are involved in a phosphorylation reaction2,3. To better understand the principles underlying these processes, we have studied the role of phosphorylation of isocitrate dehydrogenase (IDH) in the regulation of the branch point between the tricarboxylic acid (TCA) cycle and the glyoxylate bypass. We report here that in the process of purifying the kinase and phosphatase, we made two surprising observations—the kinase and phosphatase activities appear to be associated with the same protein, and the phosphatase activity has an absolute requirement for ATP.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Krebs, E. G. & Beavo, J. A. A. Rev. Biochem. 48, 923–959 (1979).

  2. 2

    Collett, M. S. & Erikson, R. L. Proc. natn. Acad. Sci. U.S.A. 75, 2021–2024 (1978).

  3. 3

    Levinson, A. D., Oppermann, H., Levintow, L., Varmus, H. E. & Bishop, J. B. Cell 15, 561–572 (1978).

  4. 4

    Kornberg, H. L. & Madsen, N. B. Biochim. biophys. Acta 24, 651–653 (1957).

  5. 5

    Bennett, P. M. & Holms, W. H. J. gen. Microbiol. 87, 37–51 (1975).

  6. 6

    Garnak, M. & Reeves, H. C. Science 203, 1111–1112 (1979).

  7. 7

    Wang, J. Y. J. & Koshland, D. E. Jr J. biol. Chem. 256, 4640–4648 (1981).

  8. 8

    Caban, C. E. & Ginsburg, A. Biochemistry 15, 1569–1580 (1976).

  9. 9

    Rhee, S. G., Park, R., Chock, P. B. & Stadtman, E. R. Proc. natn. Acad. Sci. U.S.A. 75, 3138–3142 (1978).

  10. 10

    El-Maghrabi, M. R., Claus, T. H., Pilkis, J., Fox, E. & Pilkis, S. J. J. biol. Chem. 257, 7603–7607 (1982).

  11. 11

    El-Maghrabi, M. R., Fox, E., Pilkis, J. & Pilkis, S. J. Biochem. biophys. Res. Commun. 106, 794–802 (1982).

Download references

Author information



Rights and permissions

Reprints and Permissions

About this article

Cite this article

LaPorte, D., Koshland, D. A protein with kinase and phosphatase activities involved in regulation of tricarboxylic acid cycle. Nature 300, 458–460 (1982). https://doi.org/10.1038/300458a0

Download citation

Further reading


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.