Brand Martin D, Pakay Julian L, Ocloo Augustine, Kokoszka Jason, Wallace Douglas C, Brookes Paul S, Cornwall Emma J
Medical Research Council Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, UK.
Biochem J. 2005 Dec 1;392(Pt 2):353-62. doi: 10.1042/BJ20050890.
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.
线粒体的基础质子传导会导致轻度解偶联，可能是代谢率的重要影响因素。质子传导途径的分子本质尚不清楚。我们发现，腺嘌呤核苷酸转位酶同工型1被敲除的小鼠肌肉线粒体的质子传导率是野生型对照的一半。在果蝇线粒体中，由应激敏感B基因编码的腺嘌呤核苷酸转位酶过表达会增加质子传导率，而低表达则会降低质子传导率，即使使用羧基苍术苷将载体完全抑制时也是如此。我们得出结论，线粒体基础质子传导率的一半至三分之二由腺嘌呤核苷酸载体催化，这与其ATP/ADP交换或脂肪酸依赖性质子泄漏功能无关。
