Division of Cardiovascular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605.
Departments of Pathology and Genetics, Yale University School of Medicine, New Haven, Connecticut 06520.
J Biol Chem. 2011 Dec 2;286(48):41253-41264. doi: 10.1074/jbc.M111.276121. Epub 2011 Oct 4.
Impaired oxidative phosphorylation (OXPHOS) is implicated in several metabolic disorders. Even though mitochondrial DNA encodes several subunits critical for OXPHOS, the metabolic consequence of activating mitochondrial transcription remains unclear. We show here that LRP130, a protein involved in Leigh syndrome, increases hepatic β-fatty acid oxidation. Using convergent genetic and biochemical approaches, we demonstrate LRP130 complexes with the mitochondrial RNA polymerase to activate mitochondrial transcription. Activation of mitochondrial transcription is associated with increased OXPHOS activity, increased supercomplexes, and denser cristae, independent of mitochondrial biogenesis. Consistent with increased oxidative phosphorylation, ATP levels are increased in both cells and mouse liver, whereas coupled respiration is increased in cells. We propose activation of mitochondrial transcription remodels mitochondria and enhances oxidative metabolism.
氧化磷酸化(OXPHOS)受损与几种代谢紊乱有关。尽管线粒体 DNA 编码了几个对 OXPHOS 至关重要的亚基,但激活线粒体转录的代谢后果尚不清楚。我们在这里表明,Leigh 综合征相关蛋白 LRP130 增加了肝内 β-脂肪酸氧化。通过收敛的遗传和生化方法,我们证明 LRP130 与线粒体 RNA 聚合酶复合物结合以激活线粒体转录。线粒体转录的激活与 OXPHOS 活性增加、超复合物增加和嵴密度增加有关,与线粒体生物发生无关。与增加的氧化磷酸化一致,细胞和小鼠肝中的 ATP 水平增加,而细胞中的偶联呼吸增加。我们提出激活线粒体转录重塑了线粒体并增强了氧化代谢。