5' Processing of Yeast Cytochrome b pre-mRNA

酵母细胞色素 b 前 mRNA 的 5 处理

• 批准号: 8804951
• 负责人: Carol Dieckmann
• 金额: $ 10万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8804951&HistoricalAwards=false
• 关键词: Processing; Yeast; Cytochrome; pre; mRNA

Mitochondrial biogenesis requires the coordinate expression of their nuclear and mitochondrial genomes. The long term goal of this research is to understand the nature of the controlling signals in the Saccharomyces cerevisiae that synchronize the production of mitochondrial proteins encoded in the separate compartments. The characterization of nuclear respiratory deficient pet mutants has identified several genes necessary for processing of mitochondrial precursor transcripts and translation of the resultant mRNAs on mitochondrial ribosomes. One group of pet mutants describes the nuclear gene CBP1, which encodes a 76,500 dalton protein that is imported into the organelle and interacts with the 5' end of the cytochrome b precursor RNA. It is planned to purify the CBP1 protein and study the interaction with substrate RNA in vitro. The CBP1 gene produces two polyA+ mRNAs, differing at the 3' end by 900 nucleotides. How and why the abundance of the RNAs is regulated by glucose repression will be investigated. A coding sequence terminates in the TATAA box for CBP1. This upstream gene is expressed as a 1.1 kb mRNA that is also under catabolite control. Deletions of this gene lead to a phenotype similar to deletion of a mitochondrial outer membrane protein gene. The sequence of the gene, will be determined. Does transcription of this gene affect expression of CBP1 and define how does the encoded protein function in the cell. At the present time we have only a sketchy understanding of how the functional integrity of subcellular organelles is maintained and modulated in response to a changing environment. In yeast the production of mitochondrial respiratory-chain components are significantly altered by changing their growth conditions. As three of the large enzyme complexes of the inner mitochondrine membrane are composed of subunits encoded both on nuclear chromosomes and on the organella genome, the change of expression due to media availability must be coordinated. Is it transcriptional or translational factors that enhance and decrease production of nuclearly encoded respiratory chain components? The answer to this question is of great importance for an understanding of mitochondrial respiration.

线粒体生物发生需要细胞核和线粒体基因组的协调表达。这项研究的长期目标是了解酿酒酵母中控制信号的本质，这些信号同步了在单独的隔室中编码的线粒体蛋白质的产生。核呼吸缺陷pet突变体的特征已经确定了线粒体前体转录物加工和线粒体核糖体上产生的mrna翻译所必需的几个基因。一组pet突变描述了核基因CBP1，该基因编码一种76,500道尔顿蛋白，该蛋白被输入细胞器并与细胞色素b前体RNA的5'端相互作用。计划在体外纯化CBP1蛋白并研究其与底物RNA的相互作用。CBP1基因产生两个polyA+ mrna，在3'端有900个核苷酸的差异。如何以及为什么rna的丰度是由葡萄糖抑制调节的将被研究。CBP1的编码序列终止于TATAA框。该上游基因表达为1.1 kb mRNA，也受分解代谢物控制。该基因的缺失导致类似于线粒体外膜蛋白基因缺失的表型。基因的序列，将被确定。该基因的转录是否会影响CBP1的表达，并确定该编码蛋白在细胞中的功能。目前，我们对亚细胞细胞器的功能完整性如何在不断变化的环境中得到维持和调节只有粗略的了解。在酵母中，线粒体呼吸链成分的产生因其生长条件的改变而显著改变。由于线粒体内膜的三个大型酶复合物是由核染色体和细胞器基因组上编码的亚基组成的，因此由于介质可用性而引起的表达变化必须协调一致。是转录因子还是翻译因子增加或减少了核编码呼吸链成分的产生？这个问题的答案对于理解线粒体呼吸非常重要。