CYTOCHROME C OXIDASE IN HEALTH AND DISEASE

细胞色素c氧化酶(COX)缺乏是线粒体神经肌病最常见的原因 人类。患有这些疾病的患者表现出不同的临床表型，包括利。 综合征、肌肉无力和脑肌病。对COX生物发生的完整理解是 对于阐明这类疾病背后的分子基础至关重要。该计划的主要目标是 拟议的研究是使用酵母作为模型来研究COX组装 在野生型细胞和具有进化保守组装因子突变的细胞中。几个具体的 我们将追求目标。1)我们最近报道了人SurMp的酵母同源物Shylp， 对大多数Leigh综合征负责，催化COX装配中间体的形成 涉及Coxlp，一个线粒体编码的COX催化亚基。Shylp在基因表达中的作用 将对Coxlp进行研究。2)最近的证据表明，这种中间体调节Cox1p的表达 在涉及其他COX代谢因子的过程中，如Mss51p和Cox14p，其机制是通过 将对这些蛋白中哪些调节COX表达进行研究。适当标记的Mss51p和Cox14p将 从高表达的酵母细胞中提纯。纯化蛋白质的可获得性将允许假设 关于他们的活动将被直接测试。3)参与调节Coxlp合成的蛋白质。 COX装配可能在它们之间进行短暂或永久的相互作用以执行其功能。这个 这些相互作用的性质将被描述。总而言之，酵母系统将作为一种手段进行探索 破译在组成的复合膜酶的组装中操作的一般原理 来自两个空间分离的遗传源的亚基多肽。酵母菌范例将是 利用生物化学和遗传学手段，全面了解Shylp和Shylp的功能 因此，Surflp也是如此，并澄清人类COX缺陷的分子基础。

Cytochrome c oxidase (COX) deficiency is the most frequent cause of mitochondrial neuromyopathiesin humans. Patients afflicted with these diseases present heterogeneous clinical phenotypes, including Leigh syndrome, muscle weakness and encephalomyopathy.A complete understanding of COX biogenesis is essential for elucidating the molecular basis underlying this group of diseases. The main objective of the proposed research is to use the yeast Saccharomycescerevisiae as a model to investigate COXassembly in wild type cells and in cells with mutations in evolutionary conservedassembly factors. Several specific aims will be pursued. 1) We have recently reported that Shylp, the yeast homologue of humanSurMp, responsible for most cases of Leigh's syndrome,catalyzes the formation of a COX assembly intermediate involving Coxlp, a mitochondrially encoded catalytic subunit of COX. The role of Shylp in expression of Coxlp will be studied. 2) More recent evidence indicates that this intermediate regulates Cox1 pexpression in a process involving other COX metabolism factors, such as Mss51p and Cox14p.The mechanisms by which these proteins regulate COX expression will be studied. Appropriately tagged Mss51p and Cox14p will be purified from over-expressing yeast cells. The availability of purified proteins will permit hypotheses concerning their activities to be tested directly. 3) The proteins involved in regulation of Coxlp synthesis by COX assembly are likely to interact transiently or permanently amongthem to perform their functions. The nature of these interactions will be characterized. In summary,the yeast system will be explored as a means of deciphering the general principles operating in the assembly of a complex membrane enzyme composed of subunit polypeptides derived from two spatially separated genetic sources. The yeast paradigm will be exploited by biochemical and genetic meansto gain a complete understanding of the function of Shylp and therefore of Surflp as well, and to clarifythe molecular basis of human COX deficiencies.