MITOCHONDRIAL DYSFUNCTION IN NNAD MUTANT FLIES AND PURKINJE CELL DEGENERATION

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 浦肯野细胞变性(PCD)小鼠是一种隐性的神经变性模型， 累及小脑和视网膜。浦肯野细胞在PCD中的死亡是戏剧性的，因为99%的浦肯野 神经元在三周内就会消失。NNA1功能丧失导致PCD，NNA1是一种高度的 保守的锌羧肽酶。为了确定PCD的基础，我们实现了两个 三管齐下的方法，结合功能丧失表型的特征 果蝇NNA1同源基因(NNAD)与PCD小鼠的蛋白质组学分析降低NNAD 功能产生了幼虫的致命性，幸存者表现出反映疾病的表型 PCD。定量蛋白质组学显示糖酵解和氧化的表达变化 磷酸化酶。NNA蛋白定位于线粒体，NNAD/NNA1缺失 产生线粒体异常，PCD小鼠表现出改变的蛋白分解过程 NNA1相互作用蛋白。我们的研究表明，NNA1功能丧失会导致 生物能量学和线粒体功能障碍，并表明PCD分享致病 具有神经退行性疾病的特征，如帕金森氏症。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Purkinje cell degeneration (pcd) mouse is a recessive model of neurodegeneration, involving cerebellum and retina. Purkinje cell death in pcd is dramatic, as >99% of Purkinje neurons are lost in three weeks. Loss-of-function of Nna1 causes pcd, and Nna1 is a highly conserved zinc carboxypeptidase. To determine the basis of pcd, we implemented a two pronged approach, combining characterization of loss-of-function phenotypes of the Drosophila Nna1 orthologue (NnaD) with proteomics analysis of pcd mice. Reduced NnaD function yielded larval lethality, with survivors displaying phenotypes that mirror disease in pcd. Quantitative proteomics revealed expression alterations for glycolytic and oxidative phosphorylation enzymes. Nna proteins localize to mitochondria, loss of NnaD / Nna1 produces mitochondrial abnormalities, and pcd mice display altered proteolytic processing of Nna1 interacting proteins. Our studies indicate that Nna1 loss-of-function results in altered bioenergetics and mitochondrial dysfunction, and suggest that pcd shares pathogenic features with neurodegenerative disorders such as Parkinson's disease.