Chemical Genetic Analysis of Mitochondrial dynamics

描述(申请人提供)：线粒体的形状和大小由频繁的分裂和融合事件决定。近年来发现，线粒体内线粒体的异常分裂和融合引起的线粒体形态缺陷可导致常染色体显性遗传性视神经萎缩(ADOA)相关的视神经退行性变和细胞凋亡。这些发现强调了细胞内线粒体分裂和融合的生理重要性。我们提出了一种化学遗传学的方法来研究线粒体膜动力学的分子机制和生理意义。通过哈佛大学化学和细胞生物学研究所进行的筛选，我们已经确定了这些过程的小分子抑制剂。到目前为止，最有效的是一种线粒体分裂抑制物，它针对线粒体分裂动力蛋白相关的GTPase，在酵母和哺乳动物细胞中发挥同样的作用。我们将利用这种抑制物来确定动力蛋白相关的GTP酶在线粒体分裂中的机制作用。我们还将从我们的筛选中确定其他候选抑制剂的特征，并确定它们的靶点，以研究线粒体分裂和融合的分子机制。我们在哺乳动物细胞培养模型系统中进一步开发我们的抑制剂，以检测线粒体膜动力学在细胞凋亡中的生理作用，并测试小分子分裂抑制剂对由线粒体功能障碍引起的视神经萎缩的治疗作用。

DESCRIPTION (provided by applicant): Mitochondrial shape and size are governed by frequent fission and fusion events. Recently, defects in mitochondrial morphological caused by aberrant mitochondrial fission and fusion in mitochondria have been found to lead to optic neurodegeneration associated with autosomal dominant optic atrophy (adOA), and in apoptosis. These findings underscore the physiological importance of mitochondrial fission and fusion in cells. We propose a chemical genetic approach to investigate both the molecular mechanisms and physiological implications of mitochondrial membrane dynamics. We have identified small molecule inhibitors of these processes through screens conducted at the Institute of Chemistry and Cell Biology at Harvard. The most potent to date is a mitochondrial fission inhibitor that targets the mitochondrial fission dynamin-related GTPase and acts with equal efficacy in yeast and mammalian cells. We will exploit this inhibitor to determine the mechanistic role of dynamin-related GTPases in mitochondrial fission. We will also characterize our other candidate inhibitors from our screen and identify their targets to examine the molecular mechanisms of both mitochondrial fission and fusion. We exploit our inhibitors further in mammalian cell culture model systems to examine the physiological role of mitochondrial membrane dynamics in apoptosis and to test the theraputic effects of small molecule fission inhibitors on optic atrophies that result from mitochondrial dysfunction.