The basal proton conductance of mitochondria depends on adenine nucleotide translocase content.
The basal proton conductance of mitochondria causes mild uncoupling and may be an important contributor to metabolic rate. The molecular nature of the proton-conductance pathway is unknown. We show that the proton conductance of muscle mitochondria from mice in which isoform 1 of the adenine nucleotide translocase has been ablated is half that of wild-type controls. Overexpression of the adenine nucleotide translocase encoded by the stress-sensitive B gene in Drosophila mitochondria increases proton conductance, and underexpression decreases it, even when the carrier is fully inhibited using carboxyatractylate. We conclude that half to two-thirds of the basal proton conductance of mitochondria is catalysed by the adenine nucleotide carrier, independently of its ATP/ADP exchange or fatty-acid-dependent proton-leak functions.
Brand
Martin D
MD
Medical Research Council Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, UK. martin.brand@mrc-dunn.cam.ac.uk
Pakay
Julian L
JL
Ocloo
Augustine
A
Kokoszka
Jason
J
Wallace
Douglas C
DC
Brookes
Paul S
PS
Cornwall
Emma J
EJ
D000818:Animals; D002417:Cattle; D019069:Cell Respiration; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006736:Horses; D008297:Male; D008564:Membrane Potentials; D051379:Mice; D018345:Mice, Knockout; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism*; D000226:Mitochondrial ADP, ATP Translocases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D011485:Protein Binding; D011522:Protons; D011817:Rabbits; D051381:Rats; D013552:Swine
D029721:Drosophila Proteins; D010743:Phospholipids; D011522:Protons; C491544:sesB protein, Drosophila; D000226:Mitochondrial ADP, ATP Translocases