Regulation and Gene Expression of Yeast Cytochrome c

酵母细胞色素c的调控及基因表达

• 批准号: 7926360
• 负责人: Fred Sherman
• 金额: $ 16.86万
• 依托单位: UNIVERSITY OF ROCHESTER
• 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 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7926360
• 关键词: Acetylation; Acetyltransferase; Address; Amino Acid Sequence; Amino Acids; Area; Binding; Binding Proteins; Biological Assay; Catalytic Domain; Cell Nucleus; Charge; Chromosomal Stability; Complex; Computer Analysis; Crystallization; Cytochrome c1; Cytoplasm; Defect; Degradation Pathway; Development; Disease; Eukaryota; Gene Expression Regulation; Genes; Genetic Screening; Goals; Hand; Histone H2A; Histones; Human; Indium; Individual; Investigation; Mediating; Messenger RNA; Methods; Molecular Chaperones; Mutation; N-terminal; Nuclear; Outcome; Pathway interactions; Pattern; Phenotype; Polymyositis; Polyribosomes; Post-Translational Protein Processing; Predisposition; Primary carcinoma of the liver cells; Production; Protein Acetylation; Proteins; RNA Processing; Research; Research Personnel; Ribosomes; Roentgen Rays; Role; Saccharomyces cerevisiae; Scleroderma; Serine; Signal Transduction; Structure; Substrate Specificity; System; Testing; Thyroid Gland; Transferase; Variant; Work; Yeasts; cytochrome c; in vitro activity; insight; mRNA Decay; mRNA Surveillance; mRNA Transcript Degradation; mRNA capping; messenger ribonucleoprotein; mutant; novel; overexpression; stem; yeast protein

DESCRIPTION (provided by applicant): We propose to continue our studies on N-terminal acetylation and on the DRN (degradation of mRNA in the nucleus) pathway in Saccharomyces cerevisiae, two areas of research that are conceptually unrelated, but that originated from investigations with the iso-1 -cytochrome c system. N-terminal acetylation is the one of most common protein modification in eukaryotes, occurring on approximately 85% of the different varieties of cytosolic mammalian proteins, on approximately 50% of yeast proteins, but rarely on prokaryotic proteins. The lack of N-terminal acetylation of at least some proteins leads to the loss or diminution of their functions. Our long term goal is the identification and characterization of N-terminal acetyltransferases (NATs), their substrates, their physical structures, and the functions of N-terminal acetylation of specific proteins. Yeast contains five NATs, designated NatA, NatB, NatC, NatD and NatE, with each having a different catalytic subunit and with all, but NatD, having auxiliary subunits. We propose to further investigate the subunit composition of NatE and to define minimal amino acid sequence required for acetylation by NatD. Studies of the physical structure of the NATs will be continued. We will determine if human and yeast NATs differ in their substrate specificity. We recently discovered a novel means of gene regulation that occurs by degrading a subset of normal mRNAs in the nucleus by a pathway designated DRN. Our working hypothesis is that DRN acts on all normal mRNAs, with the degree of degradation dependent on the degree of their nuclear retention. The major components of DRN are a subunit of the nuclear cap binding complex, Cbdp, and a nuclear exosome component, Rrp6p. Furthermore, DRN activity is regulated by the level of Cbdp; deletion of Cbdp diminishes DRN, whereas overproduction enhances DRN. We further suggested that these special class of normal mRNAs are differentially retained in the nucleus because of difference in their structures. We propose to continue our studies on the further characterization of DRN by identifying unknown components of the system and unknown elements in mRNAs causing susceptibility to DRN. Our studies with yeast have direct bearings to normal and pathological conditions of humans, including, for example, diseases such as polymyositis and scleroderma, which have diminutions in Rrp6p. Human NAT subunits are essential for development and are over-expressed in thyroid and hepatocellular carcinomas.

描述（由申请人提供）：我们建议继续研究酿酒酵母中的N-末端乙酰化和DRN（细胞核中mRNA的降解）途径，这两个研究领域在概念上不相关，但源于iso-1-细胞色素c系统的研究。N-末端乙酰化是真核生物中最常见的蛋白质修饰之一，发生在约85%的不同种类的胞质哺乳动物蛋白质上，约50%的酵母蛋白质上，但很少发生在原核生物蛋白质上。至少一些蛋白质的N-末端乙酰化的缺乏导致其功能的丧失或减少。我们的长期目标是鉴定和表征N-末端乙酰转移酶（NAT），它们的底物，它们的物理结构，以及特定蛋白质的N-末端乙酰化的功能。酵母含有五种NAT，命名为NatA、NatB、NatC、NatD和NatE，每种NAT具有不同的催化亚基，并且除了NatD之外，所有NAT都具有辅助亚基。我们建议进一步研究亚基组成的NatE和定义所需的最小氨基酸序列乙酰化的NatD。对NAT物理结构的研究将继续进行。我们将确定人类和酵母NAT在底物特异性方面是否不同。我们最近发现了一种新的基因调控手段，它是通过一种称为DRN的途径降解细胞核中的一部分正常mRNA而发生的。我们的工作假设是DRN作用于所有正常的mRNA，其降解程度取决于其核保留的程度。DRN的主要组分是核帽结合复合物的亚基Cbdp和核外泌体组分Rrp6p。此外，DRN活性受Cbdp水平的调节; Cbdp的缺失减少DRN，而过量产生增强DRN。我们进一步表明，这些特殊类别的正常mRNA的差异保留在细胞核中，因为它们的结构的差异。我们建议继续我们的研究进一步表征DRN的系统和未知的成分在mRNA中引起DRN的易感性。我们对酵母的研究与人类的正常和病理状况有直接关系，包括例如具有Rrp6p减少的疾病如多发性肌炎和硬皮病。人NAT亚基对发育至关重要，并且在甲状腺癌和肝细胞癌中过表达。