Interaction of ubiquinone & complex I control longevity

描述（由申请人提供）：这项工作的长期目标是在分子水平上了解线粒体功能如何影响衰老过程。我们正在研究两种具有影响线粒体功能的突变的秀丽隐杆线虫菌株，它们已经改变了寿命。这些突变株clk-1和gas-1降低了电子传递链复合体I的功能。然而，它们在寿命、对氧的敏感性和线粒体蛋白氧化损伤的积累方面存在差异。这两种菌株在自由基损伤方面的差异是很奇怪的，因为突变都影响了泛醌与复合体i的相互作用。泛醌与复合体n的相互作用已经被证明在自由基形成中起作用，并对寿命产生影响。突变体clk-1缺乏泛醌的合成，泛醌是复合物I和复合物ii的电子受体。为了生存，这种突变菌株必须从它赖以为生的细菌中获得泛素。然而，clk-1从作为食物的大肠杆菌的常见形式中获得的泛素与普通线虫的泛素（即Q8而不是Q9）不同，并给菌株带来了延长的寿命。我们发现复合体I和n在使用新泛醌的能力上有所不同；复合体n功能正常，复合体I受到严重抑制。第二个突变gas-1影响复合体I的49 kDa亚基，并形成复合体I泛素结合位点的一部分。当我们构建双突变clk-1/gas-1时，产生的动物不育，但寿命是正常动物的两倍多（34天比15天）。因此，当气体-1暴露于Q8时，它的寿命会延长。我们假设泛素与复合物I的相互作用直接影响呼吸，并对ROS的产生产生次要影响。此应用程序的具体目标是：1。测定外源性泛醌取代线粒体N2、clk-1和gas-1对呼吸的影响2. 测定线粒体中N2、gas-1和clk-1产生ROS的位点和速率；3. 证明泛醌对线粒体蛋白氧化的影响；4. 描述抑制gas-1寿命缩短的两个突变体，seg-1和seg-2。这些结果将首次证明泛素对呼吸的影响与对寿命的影响之间的相关性。

DESCRIPTION (provided by applicant): The long-term goal of this work is to understand at the molecular level how mitochondrial function affects the aging process. We are studying two strains of C. elegans with mutations affecting mitochondrial function and which have altered lifespans. These mutant strains, clk-1 and gas-1, decrease the function of complex I of the electron transport chain. However, they differ in lifespan, sensitivity to oxygen, and accumulation of oxidative damage to mitochondrial proteins. The difference in free radical damage between the two strains is curious, since the mutations both affect the interaction of ubiquinone with complex I. The role of ubiquinone interaction with complex n has already been shown to play a role hi free radical formation with resulting effects on lifespan. The mutant clk-1 is deficient in the synthesis of ubiquinone, the electron acceptor for complexes I and ll. To survive, this mutant strain must obtain its ubiquinone from the bacteria on which it feeds. However, the ubiquinone which clk-1 obtains from the common form of E. coli used as food is different than the normal nematode ubiquinone (i.e. Q8 instead of Q9) and conveys a prolonged lifespan to the strain. We found that complex I and n differ in their ability to use the new ubiquinone; complex n functions normally while complex I is severely inhibited. The second mutation, gas-1, affects the 49 kDa subunit of complex I and forms part of the ubiquinone binding site of complex I. When we constructed the double mutant clk-1/gas-1 the resulting animals are sterile but live over twice as long as normal (34 days vs. 15 days). Thus, when gas-1 is exposed to Q8, it develops a prolonged lifespan. We hypothesize that the ubiquinone interaction with complex I directly affects respiration with secondary effects on ROS production. The specific aims of this application are to: 1. Measure the effects on respiration of substituting exogenous ubiquinones into mitochondria of N2, clk-1 and gas-1; 2. Determine the sites and rates of ROS production by mitochondria from N2, gas-1, and clk-1; 3. Demonstrate the resulting effects of the ubiquinones on oxidation of mitochondrial proteins; 4. Characterize two mutants, seg-1 and seg-2, that suppress the shortened lifespan of gas-1. These results will, for the first time, allow a correlation of the effects of ubiquinone on respiration with those on lifespan.