Molecular Genetics of Mammalian Cytochrome c Oxidase

哺乳动物细胞色素 c 氧化酶的分子遗传学

• 批准号: 8905285
• 负责人: Lawrence Grossman
• 金额: $ 29.8万
• 依托单位: Wayne State University School of Medicine
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-09-01 至 1993-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8905285&HistoricalAwards=false
• 关键词: Molecular; Genetics; Mammalian; Cytochrome; Oxidase

Cytochrome c oxidase, the terminal protein of the electron transport chain, is composed in mammals of thirteen subunits, three encoded by mitochondrial DNA and the remainder by nuclear DNA. In addition to the fact that the function is unknown for all ten of the nuclear-encoded subunits, a second level of complexity has been introduced by the finding that at least three, probably more, and possibly even all of these nuclear subunits occur in more than one cellular form (isoforms). We will (1) focus on two subunits of cytochrome c oxidase, VIIa and VIIc, that are present as isoforms in order to (a) isolate and characterize cDNAs for each isoform, and (b) determine the mechanism by which these isoforms arise by examining their transcripts and the organization of their coding regions in the genome; (2) seek insights into the role of these isoforms by examining the distribution of their transcripts in various adult bovine tissues, and in tissues taken from several different developmental stages; and (3) investigate the regulation of these and other cytochrome c oxidase subunits for which we have probes by observing their stoichiometry in cultured bovine cells, particularly after perturbation of the synthesis of specific subunits with antisense transcripts. How a complex protein such as cytochrome c oxidase is correctly assembled is obscure. Even more mysterious are the mechanisms involved in the synchronous regulation of gene expression, particularly when some are located on the nuclear genome and others on the organelle genome, so that the proper ration of subunits to be assembled results. The results of this study will give us little more insight into that complex process.

细胞色素 c 氧化酶是电子传递链的末端蛋白，在哺乳动物中由 13 个亚基组成，其中三个由线粒体 DNA 编码，其余由核 DNA 编码。 除了所有十个核编码亚基的功能都是未知的事实之外，由于发现至少三个，可能更多，甚至可能所有这些核亚基以更多的形式出现，因此引入了第二个复杂性级别。多于一种细胞形式（异构体）。 我们将 (1) 重点关注以异构体形式存在的细胞色素 C 氧化酶的两个亚基 VIIa 和 VIIc，以便 (a) 分离和表征每种异构体的 cDNA，以及 (b) 确定这些异构体产生的机制检查它们的转录本和基因组中编码区域的组织； (2) 通过检查这些亚型的转录本在各种成年牛组织和取自几个不同发育阶段的组织中的分布，深入了解这些亚型的作用； (3) 通过观察培养的牛细胞中的化学计量，特别是在用反义转录物扰动特定亚基的合成之后，研究我们有探针的这些和其他细胞色素c氧化酶亚基的调节。 诸如细胞色素c氧化酶之类的复杂蛋白质如何正确组装尚不清楚。 更神秘的是基因表达同步调节所涉及的机制，特别是当一些位于核基因组上而另一些位于细胞器基因组上时，从而产生适当比例的亚基组装结果。 这项研究的结果将使我们对这个复杂的过程有更多的了解。