Chemical Genetic Analysis of Mitochondrial dynamics

描述（由申请人提供）：线粒体的形状和大小由频繁的裂变和融合事件控制。近年来，研究发现线粒体分裂和融合引起的线粒体形态学缺陷可导致常染色体显性视神经萎缩（adOA）相关的视神经变性和细胞凋亡。这些发现强调了细胞中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方法来研究线粒体膜动力学的分子机制和生理意义。我们已经通过在哈佛化学和细胞生物学研究所进行的筛选确定了这些过程的小分子抑制剂。迄今为止，最有效的是一种线粒体裂变抑制剂，其靶向线粒体裂变动力蛋白相关的GTdR，并在酵母和哺乳动物细胞中发挥同等功效。我们将利用这种抑制剂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表征我们的其他候选抑制剂，并确定它们的靶点，以研究线粒体分裂和融合的分子机制。我们进一步利用我们的抑制剂在哺乳动物细胞培养模型系统中，以检查线粒体膜动力学在细胞凋亡中的生理作用，并测试小分子裂变抑制剂对线粒体功能障碍导致的视神经萎缩的治疗效果。

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.