Mechanism of Protein Synthesis in Mammalian Mitochondria

哺乳动物线粒体蛋白质合成机制

• 批准号: 7103795
• 负责人: LINDA L SPREMULLI
• 金额: $ 34.94万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-05-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7103795
• 关键词: X ray crystallography; aminoacid tRNA ligase; aminoacyl tRNA; animal tissue; cell component structure /function; fluorescent dye /probe; genetic regulation; genetic translation; intermolecular interaction; membrane proteins; messenger RNA; methionine; mitochondrial DNA; mitochondrial membrane; molecular site; protein biosynthesis; protein structure function; ribosomal proteins; ribosomes; site directed mutagenesis; structural biology; translation factor

DESCRIPTION (provided by applicant): The generation of energy in mammalian mitochondria is accomplished by a series of oligomeric complexes in the inner membrane. The synthesis and assembly of these complexes requires genetic information ;contained in both the nuclear and mitochondrial genomes. Limited information is available on the mechanism by which the mitochondrially-encoded components in these complexes are synthesized and assembled into the large oligomeric complexes in the inner membrane. The overall objective of this research is to investigate the mechanism of protein biosynthesis in mammalian mitochondria and its integration into the macromolecular metabolism of this organelle. The first objective is focused on polypeptide chain initiation and is designed to provide an understanding of the roles and mechanism of action of two translational initiation factors required for protein biosynthesis in mammalian mitochondria. Studies will be carried out to examine their binding sites on ribosomes and to investigate their interactions with other components of the protein biosynthetic machinery. In addition, the secondary structure of the RNA near the start sites in mitochondrial mRNAs will be probed. The second major objective focuses on the properties of the translation elongation factor (EF-Tumt) that promotes the binding of aminoacyl-tRNA to the A-site of the ribosome. A collaborative project has been established with the laboratory of Dr. Soren Thirup (Univ. Aarhus, Denmark) to determine the structures of the ternary complex (EF-Tumt:GTP:aa-tRNA) and several other components of the translational cycle in mammalian mitochondria. These structural insights will lay the foundation for understanding the properties of the unusual tRNAs found in mammalian mitochondria. The third major aim of this project is to examine the interaction of the mitochondrial ribosome with the inner membrane. All of the products of mammalian mitochondrial protein biosynthesis are hydrophobic membrane proteins, which are thought to be synthesized while the ribosome is associated with the inner membrane. The interaction of the ribosome with the transmembrane protein Oxal will be studied and the parameters governing the binding of the ribosome to the inner membrane will be investigated. Well over 100 disease states in humans are associated with alterations in mitochondrial function and gene expression. Understanding protein synthesis in this organelle is essential for developing strategies to combat these diseases.

描述（由申请人提供）：哺乳动物线粒体中能量的产生是通过内膜中一系列的低聚络合物来完成的。这些复合物的合成和组装需要遗传信息；核和线粒体基因组中均包含。有限的信息可获得有关这些络合物中线粒体编码的成分的机制，并将其合成并组装到内膜中的大型低聚体络合物中。这项研究的总体目的是研究哺乳动物线粒体中蛋白质生物合成的机制及其整合到该细胞器的大分子代谢中。第一个目标集中在多肽链开始上，旨在提供对哺乳动物线粒体蛋白质生物合成所需的两个转化起始因子的作用和作用机理的理解。将进行研究以检查其在核糖体上的结合位点，并研究它们与蛋白质生物合成机械的其他成分的相互作用。另外，将探测线粒体mRNA的起始位点附近的RNA的二级结构。第二个主要目标侧重于翻译伸长因子（EF-TUMT）的特性，该因子促进了氨基酰基-TRNA与核糖体A位点的结合。已经与Soren Thirup博士（丹麦大学Aarhus）的实验室建立了一个合作项目，以确定三元建筑群（EF-TUMT：GTP：AA-TRNA）的结构和哺乳动物转换周期的其他几个组成部分线粒体。这些结构见解将为理解哺乳动物线粒体中发现的异常TRNA的特性奠定基础。该项目的第三个主要目的是检查线粒体核糖体与内膜的相互作用。哺乳动物线粒体蛋白生物合成的所有产物都是疏水膜蛋白，核糖体与内膜相关时被认为是合成的。将研究核糖体与跨膜蛋白草原的相互作用，并研究控制核糖体与内膜结合的参数。人类中有100多个疾病状态与线粒体功能和基因表达的改变有关。了解该细胞器中的蛋白质合成对于制定对抗这些疾病的策略至关重要。