Functional analysis of lymphoblast and cybrid mitochondria containing the 3460, 11778, or 14484 Leber's hereditary optic neuropathy mitochondrial DNA mutation
Functional analysis of lymphoblast and cybrid mitochondria containing the 3460, 11778, or 14484 Leber's hereditary optic neuropathy mitochondrial DNA mutation
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DOI：
10.1074/jbc.m006476200
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发表时间：
2000-12-22
影响因子：
4.8
通讯作者：
Wallace, DC
中科院分区：
文献类型：
--
作者：
Brown, MD;Trounce, IA;Wallace, DC
Leber遗传性视神经病变（LHON）是一种由线粒体DNA（mtDNA）复合物I基因突变引起的失明。我们报告了一个广泛的生化分析的线粒体缺陷的淋巴母细胞和transmitochondrial cybrids窝藏三个最常见的LHON突变：3460 A，11778 A，和14484 C。呼吸研究表明，3460 A突变使最大呼吸速率降低20- 28%，11778 A突变降低30- 36%，14484 C突变降低10- 15%。在胞质杂种实验中转移的3460 A和11778 A突变的呼吸缺陷将这些缺陷与mtDNA联系起来。复合物I酶促测定显示，3460 A突变导致比活性降低79%，11778 A突变导致比活性降低20%，而14484 C突变不影响复合物I活性。胞质杂种线粒体DNA 3460 A突变的酶缺陷总的来说，这些数据支持3460 A和11778 A突变体导致复合物I缺陷和14484 C突变导致更温和的生化缺陷的结论。这些研究代表了所有主要LHON线粒体DNA突变中氧化磷酸化缺陷的首次直接比较，从而使人们能够深入了解该疾病的潜在病理生理机制。
Leber's hereditary optic neuropathy (LHON) is a form of blindness caused by mitochondrial DNA (mtDNA) mutations in complex I genes. We report an extensive biochemical analysis of the mitochondrial defects in lymphoblasts and transmitochondrial cybrids harboring the three most common LHON mutations: 3460A, 11778A, and 14484C. Respiration studies revealed that the 3460A mutation reduced the maximal respiration rate 20-28%, the 11778A mutation 30-36%, and the 14484C mutation 10-15%. The respiration defects of the 3460A and 11778A mutations transferred in cybrid experiments linking these defects to the mtDNA. Complex I enzymatic assays revealed that the 3460A mutation resulted in a 79% reduction in specific activity and the 11778A mutation resulted in a 20% reduction, while the 14484C mutation did not affect the complex I activity. The enzyme defect of the 3460A mutation transferred with the mtDNA in cybrids. Overall, these data support the conclusion that the 3460A and 11778A mutants result in complex I defects and that the 14484C mutation causes a much milder biochemical defect. These studies represent the first direct comparison of oxidative phosphorylation defects among all of the primary LHON mtDNA mutations, thus permitting insight into the underlying pathophysiological mechanism of the disease.