Mitochondrial cysteine desulfurase

线粒体半胱氨酸脱硫酶

• 批准号: 7937766
• 负责人: ANDREW B. DANCIS
• 金额: $ 33.16万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7937766
• 关键词: Active Sites; Anemia; Bacteria; Biochemical Genetics; Biogenesis; Cell Survival; Cells; Complex; Cysteine; DNA Repair; Data; Defect; Disease; Enzymes; Eukaryotic Cell; Exhibits; Friedreich Ataxia; Functional disorder; Genes; Genome Stability; Human; Iceberg; In Vitro; Inner mitochondrial membrane; Iron; Iron-Sulfur Proteins; Life; Malignant Neoplasms; Mammals; Membrane; Methods; Mitochondria; Mitochondrial Myopathies; Mitochondrial Proteins; Mutation; Nature; Nerve Degeneration; Nuclear; Physiological; Process; Proteins; Regulation; Role; Saccharomyces cerevisiae; Scaffolding Protein; Sideroblastic Anemia; Sulfides; Sulfur; Testing; Time; Transfer RNA; Yeasts; cysteine desulfurase; in vivo; mutant; persulfides; prevent; protein complex; research study; trafficking; yeast protein

Cysteine desulfurases perform essential functions in releasing sulfur from cysteine, forming a covalent persulfide, and channeling the persulfide sulfur to biologically critical recipients e.g. ironsulfur (Fe-S) clusters and thiolated tRNAs. The activity of cysteine desulfurase cannot be replaced by exogenously supplied sulfide or by other sulfur metabolizing enzymes, and thus cysteine desulfurase is essential for cell viability. The eukaryotic cysteine desulfurase is encoded by a single nuclear gene and is found primarily in mitochondria. In Saccharomyces cerevisiae mitochondria, the cysteine desulfurase protein Nfs1 is assembled in a large protein complex with a recently identified special accessory protein called Isd11. We found that Isd11 is required for Nfs1 cysteine desulfurase activity. Thus, Nfs1 and Isd11 expressed together in bacteria are assembled into an active complex, while these components expressed separately are inactive. Here we propose to characterize the active Nfs1/Isd11 complex, and regulation of its cysteine desulfurase activity by Fe-S cluster scaffold proteins, Isu. Aim 1 is to determine the role of yeast Isd11 in the active Nfs1/Isd11 cysteine desulfurase complex. Experiments will be performed using bacterial expressed and purified proteins, and also in a more physiological context using isolated intact mitochondria. Aim 2 is to characterize formation of persulfide sulfur on Nfs1/Isd11 in isolated intact mitochondria, with focus on the regulatory effect of the D37A mutation of Isu. The significance derives from the essential role of cysteine desulfurase for viability of all human cells. The enzyme is found primarily in mitochondria and is required for Fe-S cluster synthesis and tRNA thiolation in mitochondria, both are essential processes. The identification of specific diseases arising from defective Fe-S cluster assembly (e.g. Friedreich's ataxia, sideroblastic anemia, and mitochondrial myopathy) represents the tip of the iceberg. The recent discovery of a key role of Fe-S clusters in DNA repair and genome stability suggests that cysteine desulfurases are involved in these processes.

半胱氨酸脱硫酶在释放半胱氨酸的硫时发挥重要功能，形成A 共价硫硫化物，并将硫化硫传递给生物学关键的受体，例如 ironsulfur（Fe-S）簇和硫醇化的TRNA。半胱氨酸脱硫酶的活性不能 被外源提供的硫化物或其他硫代谢酶取代，因此 半胱氨酸脱硫酶对于细胞活力至关重要。真核半胱氨酸脱硫酶是编码的 由单个核基因，主要在线粒体中发现。在酿酒酵母中 线粒体，半胱氨酸脱硫酶蛋白NFS1在大型蛋白质复合物中组装在一起 最近鉴定出的称为ISD11的特殊辅助蛋白。我们发现ISD11是必需的 NFS1半胱氨酸脱硫酶活性。因此，在细菌中一起表达的NFS1和ISD11是 组装成一个活跃的复合物，而这些分别表达的成分是不活跃的。 在这里，我们建议表征活性NFS1/ISD11复合物及其半胱氨酸的调节 Fe-S簇支架蛋白ISU的脱硫酶活性。目标1是确定酵母的作用 活性NFS1/ISD11半胱氨酸脱硫酶配合物中的ISD11。实验将使用 细菌表达和纯化的蛋白质，并且在更生理的环境中使用孤立的蛋白质 完整的线粒体。 AIM 2是表征在NFS1/ISD11上形成的硫化物硫的形成 分离的完整线粒体，重点是ISU D37A突变的调节作用。 其意义来自半胱氨酸脱硫酶对所有人的生存能力的基本作用 细胞。该酶主要在线粒体中发现，是Fe-S簇合成所必需的 线粒体中的tRNA硫醇化都是必不可少的过程。特定的识别 由Fe-S簇组装有缺陷引起的疾病（例如Friedreich的共济失调，Sideroblastic 贫血，线粒体肌病）代表冰山一角。最近发现 Fe-S簇在DNA修复和基因组稳定性中的关键作用表明半胱氨酸脱硫酶 参与了这些过程。