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Coenzyme Q is an obligatory cofactor for uncoupling protein function

Nature volume 408, pages 609–613 (2000)Cite this article

Abstract

Uncoupling proteins (UCPs) are thought to be intricately controlled uncouplers1,2,3 that are responsible for the futile dissipation of mitochondrial chemiosmotic gradients, producing heat rather than ATP. They occur in many animal and plant cells4,5,6,7,8,9 and form a subfamily of the mitochondrial carrier family10. Physiological uncoupling of oxidative phosphorylation must be strongly regulated to avoid deterioration of the energy supply and cell death, which is caused by toxic uncouplers. However, an H+ transporting uncoupling function is well established only for UCP1 from brown adipose tissue2,8,9,11, and the regulation of UCP1 by fatty acids, nucleotides and pH remains controversial2,12,13,14. The failure of UCP1 expressed in Escherichia coli inclusion bodies to carry out fatty-acid-dependent H+ transport activity inclusion bodies15 made us seek a native UCP cofactor. Here we report the identification of coenzyme Q (ubiquinone) as such a cofactor. On addition of CoQ10 to reconstituted UCP1 from inclusion bodies, fatty-acid-dependent H+ transport reached the same rate as with native UCP1. The H+ transport was highly sensitive to purine nucleotides, and activated only by oxidized but not reduced CoQ. H+ transport of native UCP1 correlated with the endogenous CoQ content.

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Figure 1: Functional integrity of refolded recombinant IB-UCP1 from E. coli.
Figure 2: Identification of CoQ as the activating component in mitochondrial lipids of H+ transport by UCP1.
Figure 3: Identification of CoQ in native isolated mitochondrial UCP1.
Figure 4: The influence of three regulatory parameters on the H+ transport activity of recombinant UCP1.

References

  1. Nicholls, D. G. & Locke, R. M. Thermogenic mechanisms in brown fat. Physiol. Rev. 64, 1–64 (1984).

    Article  CAS  Google Scholar 

  2. Klingenberg, M. & Huang, S.-G. Structure and function of the uncoupling protein from brown adipose tissue. Biochim. Biophys. Acta 1415, 271–296 (1999).

    Article  CAS  Google Scholar 

  3. Nedergaard, J. & Cannon, B. The uncoupling portein thermogenin and mitochondrial thermogenesis. New Comp. Biochem. 23, 385–420 (1992).

    Article  CAS  Google Scholar 

  4. Fleury, C. et al. Uncoupling protein-2: a novel gene linked to obesity and hyperinsulinemia. Nature Genet. 15, 269–272 (1997).

    Article  CAS  Google Scholar 

  5. Boss, O. et al. Uncoupling protein-3: a new member of the mitochondrial carrier family with tissue-specific expression. FEBS Lett. 408, 39–42 (1997).

    Article  ADS  CAS  Google Scholar 

  6. Mao, W. et al. UCP4, a novel brain-specific mitochondrial protein that reduces membrane potential in mammalian cells. FEBS Lett. 43, 326–330 (1999).

    Article  Google Scholar 

  7. Laloi, M. et al. Plant cold-induced uncoupling protein. Nature 389, 135–136 (1997).

    Article  ADS  CAS  Google Scholar 

  8. Boss, O., Muzzin, P. & Giacobino, J. P. The uncoupling proteins, a review. Eur. J. Endocrinol. 139, 1–9 (1998).

    Article  CAS  Google Scholar 

  9. Ricquier, D. & Bouillaud, F. The uncoupling protein homologues: UCP1, UCP2, UCP3, StUCP and AtUCP. Biochem. J. 345, 161–179 (2000).

    Article  CAS  Google Scholar 

  10. Aquila, H., Link, T. A. & Klingenberg, M. Solute carriers involved in energy transfer of mitochondria form a homologous protein family. FEBS Lett. 212, 1–9 (1987).

    Article  CAS  Google Scholar 

  11. Lin, C. S. & Klingenberg, M. Characteristics of the isolated purine nucleotide binding protein from brown fat mitochondria. Biochemistry 21, 2950–2956 (1982).

    Article  CAS  Google Scholar 

  12. Jezek, P., Orosz, D. E., Modriansky, M. & Garlid, K. D. Transport of anions and protons by the mitochondrial uncoupling protein and its regulation by nucleotides and fatty acids. A new look at old hypotheses. J. Biol. Chem. 269, 26184–26190 (1994).

    CAS  PubMed  Google Scholar 

  13. Gonzalez-Barroso, M. M., Fleury, C., Bouillaud, F., Nicholls, D. G. & Rial, E. The uncoupling protein UCP1 does not increase the proton conductance of the inner mitochondrial membrane by functioning as a fatty acid anion transporter. J. Biol. Chem. 273, 15528–15532 (1998).

    Article  CAS  Google Scholar 

  14. Matthias, A., Jacobsson, A., Cannon, B. & Nedergaard, J. The bioenergetics of brown fat mitochondria from UCP1-ablated mice. Ucp1 is not involved in fatty acid-induced de-energization (“uncoupling”). J. Biol. Chem. 274, 28150–28160 (1999).

    Article  CAS  Google Scholar 

  15. Echtay, K. S. et al. Regulation of UCP3 by nucleotides is different from regulation of UCP1. FEBS Lett. 450, 8–12 (1999).

    Article  CAS  Google Scholar 

  16. Murdza-Inglis, D. L. et al. Functional reconstitution of rat uncoupling protein following its high level expression in yeast. J. Biol. Chem. 266, 11871–11875 (1991).

    CAS  PubMed  Google Scholar 

  17. Arechaga, I. et al. Cysteine residues are not essential for uncoupling protein function. Biochem. J. 296, 693–700 (1993).

    Article  CAS  Google Scholar 

  18. Echtay, K. S., Bienengraeber, M. & Klingenberg, M. Mutagenesis of the uncoupling protein of brown adipose tissue. Neutralization of E190 largely abolishes pH control of nucleotide binding. Biochemistry 36, 8253–8260 (1997).

    Article  CAS  Google Scholar 

  19. Bathgate, B., Freebairn, E. M., Greenland, A. J. & Reid, G. A. Functional expression of the rat brown adipose tissue uncoupling protein in Saccharomyces cerevisiae. Mol. Microbiol. 6, 363–370 (1992).

    Article  CAS  Google Scholar 

  20. Jaburek, M. et al. Transport function and regulation of mitochondrial uncoupling proteins 2 and 3. J. Biol. Chem. 274, 26003–26007 (1999).

    Article  CAS  Google Scholar 

  21. Huang, S.-G. & Klingenberg, M. Fluorescent nucleotide derivatives as specific probes for the uncoupling protein: thermodynamics and kinetics of binding and the control by pH. Biochemistry 34, 349–360 (1995).

    Article  CAS  Google Scholar 

  22. Winkler, E., Wachter, E. & Klingenberg, M. Identification of the pH sensor for nucleotide binding in the uncoupling protein from brown adipose tissue. Biochemistry 36, 148–155 (1997).

    Article  CAS  Google Scholar 

  23. Skulachev, V. P. Fatty acid circuit as a physiological mechanism of uncoupling of oxidative phosphorylation. FEBS Lett. 294, 158–162 (1991).

    Article  CAS  Google Scholar 

  24. Brustovetsky, N. & Klingenberg, M. The reconstituted ADP/ATP carrier can mediate H+ transport by free fatty acids, which is further stimulated by mersalyl. J. Biol. Chem. 269, 27329–27336 (1994).

    CAS  PubMed  Google Scholar 

  25. Winkler, E. & Klingenberg, M. Effect of fatty acids on H+ transport activity of the reconstituted uncoupling protein. J. Biol. Chem. 269, 2508–2515 (1994).

    CAS  PubMed  Google Scholar 

  26. Fiermonte, G., Walker, J. & Palmieri, F. Abundant bacterial expression and reconstitution of an intrinsic membrane transport protein from bovine mitochondria. Biochem. J. 294, 293–299 (1993).

    Article  CAS  Google Scholar 

  27. Kaplan, R. S. High-level bacterial expression of mitochondrial transport proteins. J. Bioenerg. Biomembr. 28, 41–47 (1996).

    Article  CAS  Google Scholar 

  28. Schroers, A., Burkovski, A., Wohlrab, H. & Kramer, R. The phosphate carrier from yeast mitochondria. Dimerization is a prerequisite for function. J. Biol. Chem. 273, 14269–14276 (1998).

    Article  CAS  Google Scholar 

  29. Kowaltowski, A. J., Costa, A. D. & Vercesi, A. E. Activation of the potato plant uncoupling mitochondrial protein inhibits reactive oxygen species generation by the respiratory chain. FEBS Lett. 425, 213–216 (1998).

    Article  CAS  Google Scholar 

  30. Walter, L. et al. Three classes of ubiquinone analogs regulate the mitochondrial permeability transition pore through a common site. J. Biol. Chem. 275, 29521–29527 (2000).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank K. Beyer for the NMR measurements. This work was supported by a grant from the Deutsche Forschungsgemeinschaft.

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Author notes

  1. Karim S. Echtay and Edith Winkler: These authors contributed equally to this work

  2. Correspondence and requests for materials should be addressed to M.K. .

Authors
  1. Karim S. Echtay
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  2. Edith Winkler
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  3. Martin Klingenberg
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Institute of Physiological Chemistry, University of Munich, Schillerstrasse 44, Munich, D-80336, Germany

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Echtay, K., Winkler, E. & Klingenberg, M. Coenzyme Q is an obligatory cofactor for uncoupling protein function. Nature 408, 609–613 (2000). https://doi.org/10.1038/35046114

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