Nuclear Gene Involvement in Cytochrome Oxidase Deficiency

核基因参与细胞色素氧化酶缺乏症

• 批准号: 6641496
• 负责人: ERIC A. SCHON
• 金额: $ 22.15万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-12-01 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6641496
• 关键词: cell line; cytochrome oxidase; enzyme biosynthesis; enzyme deficiency; enzyme mechanism; enzyme structure; fibroblasts; gene complementation; genetic disorder; genetic mapping; genetic screening; human tissue; isozymes; molecular pathology; patient oriented research

Cytochrome c oxidase (COX), or complex IV of the mitochondrial respiratory chain, is a copper- and hemecontaining metalloprotein composed of 13 subunits, 3 encoded by mitochondrial DNA (mtDNA) and 10 by nuclear DNA (nDNA). A number of COX-deficiency disorders are associated with point mutations in mtDNAencoded COX subunits, but very little is known regarding the molecular basis of mendelian-inherited COX deficiency disorders, which display widely varying phenotypes, including both generalized and tissuespecific clinical presentations. In particular, no mutation in any of the 10 nDNA-encoded COX subunits has yet been found. In the last four years, however, mutations have been found in four COX assembly genes - COX10 , SC01, SC02, and SURF1. We believe that other such genes exist, and propose to identify them by screening our large collection of fibroblasts from patients with COX deficiency. We propose to first, screen for "obvious" candidate genes among the known COX structural and assembly genes. Among those cell lines which survive this first screen, we will use functional complementation by a combination of rodent-human monochromosomal hybrids and microcell-mediated chromosomal transfer to identify complementation groups and candidate chromosomal loci. The culprit genes at these loci will be identified by a combination of microsatelle and deletion mapping, coupled with a judicious sequencing of candidate genes in the region. Any new gene thus identified will be characterized as to its role in COX structure, function, and tissue-specific expression. Uncovering the molecular basis of COX deficiency will be useful in terms of pointing the way to diagnosis and treatment of these generally fatal and untreatable disorders. Moreover, these errors will be extremely useful in understanding fundamental biological phenomena, such as COX holoenzyme assembly, COX function, mitochondrial importation, and energy utilization and production. There are no naturally occurring COX mutants in higher eukaryotes other than those causing the diseases outlined above. Thus, elucidating the molecular basis of the COX deficiencies will afford us new and useful insights from both a clinical and scientific standpoint.

细胞色素c氧化酶（Cytochrome c oxidase，考克斯），又称线粒体呼吸链复合物IV，是一种含铜和血红素的金属蛋白，由13个亚基组成，其中3个由线粒体DNA（mtDNA）编码，10个由核DNA（nDNA）编码。许多COX缺陷性疾病与mtDNA编码的考克斯亚基的点突变有关，但对孟德尔遗传的考克斯缺陷性疾病的分子基础知之甚少，这些疾病表现出广泛不同的表型，包括全身性和组织特异性临床表现。特别是，尚未发现10个nDNA编码的考克斯亚基中的任何突变。 然而，在过去的四年中，在四个考克斯组装基因中发现了突变-COX 10，SC 01，SC 02和SURF 1。我们相信，其他这样的基因存在，并建议通过筛选我们的大量收集成纤维细胞与考克斯缺陷的患者来确定他们。我们建议首先在已知的考克斯结构和组装基因中筛选“明显”的候选基因。 在第一次筛选后存活的细胞系中，我们将使用啮齿动物-人单染色体杂交和微细胞介导的染色体转移相结合的功能互补来鉴定互补组和候选染色体位点。 这些基因座上的罪魁祸首基因将通过以下方法的组合来鉴定： 微卫星和缺失作图，再加上该地区候选基因的明智测序。 因此，任何新的基因将被鉴定其在考克斯结构、功能和组织特异性表达中的作用。 揭示考克斯缺乏症的分子基础将有助于为这些通常致命和无法治疗的疾病的诊断和治疗指明方向。 此外，这些错误将是非常有用的理解基本的生物现象，如考克斯全酶组装，考克斯功能，线粒体输入，能源利用和生产。 在高等真核生物中，除了引起上述疾病的突变体外，没有天然存在的考克斯突变体。 因此，阐明考克斯缺陷的分子基础将为我们提供新的和有用的见解，从临床和科学的角度。