MITOCHONDRIAL DYSFUNCTION IN NNAD MUTANT FLIES AND PURKINJE CELL DEGENERATION

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 浦肯野细胞变性(PCD)小鼠是一种隐性神经变性模型，累及小脑和视网膜。PCD的浦肯野细胞死亡是戏剧性的，因为99%的浦肯野神经元在三周内消失。NNA1功能丧失会导致PCD，而NNA1是一种高度保守的锌羧肽酶。为了确定PCD的基础，我们实施了一种双管齐下的方法，将果蝇NNA1同源基因(NNAD)功能丧失表型的表征与PCD小鼠的蛋白质组学分析相结合。NNAD功能降低导致幼虫死亡，幸存者表现出反映PCD疾病的表型。定量蛋白质组学显示糖酵解和氧化磷酸化酶的表达变化。NNA蛋白定位于线粒体，NNAD/NNA1缺失导致线粒体异常，PCD小鼠表现出NNA1相互作用蛋白的蛋白分解过程改变。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的改变，并表明PCD与帕金森病等神经退行性疾病具有共同的致病特征。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.