Role of the Transmembrane Potential in the Membrane Proton Leak

Overview

Journal Biophys J

Publisher Cell Press

Specialty Biophysics

Date 2010 Apr 23

PMID 20409469

Citations 46

Authors

Anne Rupprecht

Elena A Sokolenko

Valeri Beck

Olaf Ninnemann

Martin Jaburek

Thorsten Trimbuch

Sergey S Klishin

Petr Jezek

Vladimir P Skulachev

Elena E Pohl

Affiliations

Soon will be listed here.

Abstract

The molecular mechanism responsible for the regulation of the mitochondrial membrane proton conductance (G) is not clearly understood. This study investigates the role of the transmembrane potential (DeltaPsim) using planar membranes, reconstituted with purified uncoupling proteins (UCP1 and UCP2) and/or unsaturated FA. We show that high DeltaPsim (similar to DeltaPsim in mitochondrial State IV) significantly activates the protonophoric function of UCPs in the presence of FA. The proton conductance increases nonlinearly with DeltaPsim. The application of DeltaPsim up to 220 mV leads to the overriding of the protein inhibition at a constant ATP concentration. Both, the exposure of FA-containing bilayers to high DeltaPsim and the increase of FA membrane concentration bring about the significant exponential Gm increase, implying the contribution of FA in proton leak. Quantitative analysis of the energy barrier for the transport of FA anions in the presence and absence of protein suggests that FA- remain exposed to membrane lipids while crossing the UCP-containing membrane. We believe this study shows that UCPs and FA decrease DeltaPsim more effectively if it is sufficiently high. Thus, the tight regulation of proton conductance and/or FA concentration by DeltaPsim may be key in mitochondrial respiration and metabolism.

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References

Skulachev V . Fatty acid circuit as a physiological mechanism of uncoupling of oxidative phosphorylation. FEBS Lett. 1991; 294(3):158-62. DOI: 10.1016/0014-5793(91)80658-p. View

Brand M, Pakay J, Ocloo A, Kokoszka J, Wallace D, Brookes P . The basal proton conductance of mitochondria depends on adenine nucleotide translocase content. Biochem J. 2005; 392(Pt 2):353-62. PMC: 1316271. DOI: 10.1042/BJ20050890. View

Echtay K, Roussel D, St-Pierre J, Jekabsons M, Cadenas S, Stuart J . Superoxide activates mitochondrial uncoupling proteins. Nature. 2002; 415(6867):96-9. DOI: 10.1038/415096a. View

Brown G, Brand M . On the nature of the mitochondrial proton leak. Biochim Biophys Acta. 1991; 1059(1):55-62. DOI: 10.1016/s0005-2728(05)80187-2. View

Lin C, Klingenberg M . Isolation of the uncoupling protein from brown adipose tissue mitochondria. FEBS Lett. 1980; 113(2):299-303. DOI: 10.1016/0014-5793(80)80613-2. View

Beck V, Jaburek M, Demina T, Rupprecht A, Porter R, Jezek P . Polyunsaturated fatty acids activate human uncoupling proteins 1 and 2 in planar lipid bilayers. FASEB J. 2007; 21(4):1137-44. DOI: 10.1096/fj.06-7489com. View

Krishnamoorthy G, HINKLE P . Non-ohmic proton conductance of mitochondria and liposomes. Biochemistry. 1984; 23(8):1640-5. DOI: 10.1021/bi00303a009. View

Stulen G . Electric field effects on lipid membrane structure. Biochim Biophys Acta. 1981; 640(3):621-7. DOI: 10.1016/0005-2736(81)90092-4. View

Krauss S, Zhang C, Lowell B . The mitochondrial uncoupling-protein homologues. Nat Rev Mol Cell Biol. 2005; 6(3):248-61. DOI: 10.1038/nrm1592. View

10.

Silva J, Shabalina I, Dufour E, Petrovic N, Backlund E, Hultenby K . SOD2 overexpression: enhanced mitochondrial tolerance but absence of effect on UCP activity. EMBO J. 2005; 24(23):4061-70. PMC: 1356306. DOI: 10.1038/sj.emboj.7600866. View

11.

Jaburek M, Garlid K . Reconstitution of recombinant uncoupling proteins: UCP1, -2, and -3 have similar affinities for ATP and are unaffected by coenzyme Q10. J Biol Chem. 2003; 278(28):25825-31. DOI: 10.1074/jbc.M302126200. View

12.

Beck V, Jaburek M, Breen E, Porter R, Jezek P, Pohl E . A new automated technique for the reconstitution of hydrophobic proteins into planar bilayer membranes. Studies of human recombinant uncoupling protein 1. Biochim Biophys Acta. 2006; 1757(5-6):474-9. DOI: 10.1016/j.bbabio.2006.03.006. View

13.

Benz R, McLaughlin S . The molecular mechanism of action of the proton ionophore FCCP (carbonylcyanide p-trifluoromethoxyphenylhydrazone). Biophys J. 1983; 41(3):381-98. PMC: 1329191. DOI: 10.1016/S0006-3495(83)84449-X. View

14.

GARLID K, Beavis A, Ratkje S . On the nature of ion leaks in energy-transducing membranes. Biochim Biophys Acta. 1989; 976(2-3):109-20. DOI: 10.1016/s0005-2728(89)80219-1. View

15.

Le Saux A, Ruysschaert J, Goormaghtigh E . Membrane molecule reorientation in an electric field recorded by attenuated total reflection Fourier-transform infrared spectroscopy. Biophys J. 2001; 80(1):324-30. PMC: 1301236. DOI: 10.1016/S0006-3495(01)76017-1. View

16.

Pohl E, Peterson U, Sun J, Pohl P . Changes of intrinsic membrane potentials induced by flip-flop of long-chain fatty acids. Biochemistry. 2000; 39(7):1834-9. DOI: 10.1021/bi9919549. View

17.

Klingenberg M, Winkler E . The reconstituted isolated uncoupling protein is a membrane potential driven H+ translocator. EMBO J. 1985; 4(12):3087-92. PMC: 554626. DOI: 10.1002/j.1460-2075.1985.tb04049.x. View

18.

Andreyev AYu , Bondareva T, Dedukhova V, Mokhova E, Skulachev V, Volkov N . Carboxyatractylate inhibits the uncoupling effect of free fatty acids. FEBS Lett. 1988; 226(2):265-9. DOI: 10.1016/0014-5793(88)81436-4. View

19.

Coster H . Electromechanical stresses and the effect of pH on membrane structure. Biochim Biophys Acta. 1975; 382(2):142-6. DOI: 10.1016/0005-2736(75)90172-8. View

20.

Wojtczak L, Wieckowski M, Schonfeld P . Protonophoric activity of fatty acid analogs and derivatives in the inner mitochondrial membrane: a further argument for the fatty acid cycling model. Arch Biochem Biophys. 1998; 357(1):76-84. DOI: 10.1006/abbi.1998.0777. View