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。我们正在研究两株C.具有影响线粒体功能的突变并改变寿命的线虫。这些突变株，ESTA-1和气体-1，降低电子传递链的复合物I的功能。然而，它们在寿命、对氧的敏感性和对线粒体蛋白的氧化损伤的积累方面不同。两种菌株之间自由基损伤的差异是奇怪的，因为突变都影响泛醌与复合物I的相互作用。泛醌与复合物n相互作用的作用已经被证明在自由基形成中起作用，从而对寿命产生影响。该突变体的α-l在复合物I和II的电子受体泛醌的合成中是缺陷的。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醌。然而，β-l从E.用作食物的大肠杆菌与正常的线虫泛醌不同（即Q8而不是Q9），并延长了菌株的寿命。我们发现，复杂的I和N不同的能力，使用新的泛醌;复杂的N功能正常，而复杂的I被严重抑制。第二个突变gas-1影响复合物I的49 kDa亚基，并形成复合物I的泛醌结合位点的一部分。当我们构建双突变体GAS-1/GAS-1时，产生的动物是不育的，但寿命是正常的两倍（34天对15天）。因此，当气体-1暴露于Q8时，其寿命延长。我们假设泛醌与复合物I的相互作用直接影响呼吸作用，并对ROS的产生次级影响。本申请的具体目的是：1.测定外源泛醌替代N2、Gas-1和Gas-1线粒体对呼吸的影响。确定线粒体从N2、Gas-1和Gas-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.描述两种突变体seg-1和seg-2的特征，这两种突变体抑制gas-1的寿命缩短。这些结果将首次允许泛醌对呼吸作用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.