tRNA editing by deamination: Balancing affinity and specificty

通过脱氨基进行 tRNA 编辑：平衡亲和力和特异性

基本信息

批准号：
8479370
负责人：
Juan D Alfonzo
金额：
$ 30.46万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-08-01 至 2016-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8479370
关键词：
Accounting Adenosine Affect Affinity Affinity Chromatography Amino Acids Anticodon Binding Biochemical Biochemical Reaction Biological Biological Assay Catalysis Cell Line Cell Nucleus Cell physiology Cells Cellular biology Chemicals Codon Nucleotides Complex Coupled Coupling Cytidine Deaminase Cytoplasm Cytosine Deaminase Deamination Disease Enzymes Epigenetic Process Equilibrium Eukaryota Event Face Family member Future Gene Expression Gene Mutation Genetic Genome Genomics Human Inosine Introns Knowledge Leishmania Link Mammals Medical Metabolic Diseases Metabolism Methylation Methyltransferase Mitochondria Modeling Modification Molecular Nature Nuclear Nucleotides Organism Outcome Parasites Pathway interactions Play Positioning Attribute Printing Process Protein Biosynthesis Protein Family Proteins RNA Interference RNA Splicing RNA-Protein Interaction Reaction Recombinants Regulation Reporter Research Role Series Site Specific qualifier value Specificity Structure Substrate Specificity System Testing Therapeutic Intervention Threonine-Specific tRNA Transfer RNA Trypanosoma Trypanosoma brucei brucei Uridine Zinc base crosslink diprotin B drug development flexibility foot in vitro activity in vivo insight leucyl-alanine member mutant novel pathogen reconstitution

Accounting Adenosine Affect Affinity Affinity Chromatography Amino Acids Anticodon Binding Biochemical Biochemical Reaction Biological Biological Assay Catalysis Cell Line Cell Nucleus Cell physiology Cells Cellular biology Chemicals Codon Nucleotides Complex Coupled Coupling Cytidine Deaminase Cytoplasm Cytosine Deaminase Deamination Disease Enzymes Epigenetic Process Equilibrium Eukaryota Event Face Family member Future Gene Expression Gene Mutation Genetic Genome Genomics Human Inosine Introns Knowledge Leishmania Link Mammals Medical Metabolic Diseases Metabolism Methylation Methyltransferase Mitochondria Modeling Modification Molecular Nature Nuclear Nucleotides Organism Outcome Parasites Pathway interactions Play Positioning Attribute Printing Process Protein Biosynthesis Protein Family Proteins RNA Interference RNA Splicing RNA-Protein Interaction Reaction Recombinants Regulation Reporter Research Role Series Site Specific qualifier value Specificity Structure Substrate Specificity System Testing Therapeutic Intervention Threonine-Specific tRNA Transfer RNA Trypanosoma Trypanosoma brucei brucei Uridine Zinc base crosslink diprotin B drug development flexibility foot in vitro activity in vivo insight leucyl-alanine member mutant novel pathogen reconstitution

展开

项目摘要

DESCRIPTION (provided by applicant): Sequence alterations that change the meaning of a tRNA in decoding are part of a growing number of post-transcriptional changes collectively known as tRNA editing. Editing can be influenced by the structural context of an editing site and in the case of tRNA can be modulated by posttranscriptional modifications. In trypanosomatids, tRNAs are transcribed in the nucleus, exported to the cytoplasm, and later a subset of cytoplasmic tRNAs is actively imported into the mitochondria. However, before tRNAs can be rendered functional in any cellular compartment, they face many enzymatic reactions including end trimming, intron splicing, tRNA editing, and chemical modification. Some of these processes, for example those involved in trimming of extraneous sequences at the tRNA ends, occur in the nucleus, usually preceding cytoplasmic export. Others, like editing and modification, may occur at any point in the tRNA maturation pathway and in any of the tRNA-containing compartments. Despite much progress made in last few years, it is still not clear how editing and modification pathways are integrated both at the molecular and cellular levels. We have proposed that tRNA editing and modification events can be highly coupled and exploited by some organisms to control gene expression at the level of tRNA specificity. This is especially important in single-cell eukaryotes like trypanosomatid parasites where is well accepted that the bulk of the genetic regulation occurs post-transcriptionally. In this proposal, we have continued our studies on the very unique tRNA editing enzyme of T. brucei but now prompted by our newly solved crystal structure we ask new questions of what makes this enzyme so unique. We also focus on a newly discovered set of methyltransferases, which surprisingly target the editing site providing a wonderful testing ground for our hypothesis of the interrelation of editing and modification and what this coupling may mean in terms of cellular function. Significantly, reconstitution of methylation activity in vitro requires addition of the recombinant editing enzyme a finding that is without precedent in the tRNA editing and modification field. As essential steps in tRNA maturation in trypanosomatids (Leishmania and Trypanosoma), these types of editing and modification events also provide very attractive targets for therapeutic intervention against parasites of very major medical importance. Given the link between tRNA maturation and disease, these studies will further expand our knowledge of the role tRNA takes as a central player in cellular metabolism. !

描述（由申请人提供）：改变tRNA在解码中的含义的序列改变是越来越多的转录后变化的一部分，共同称为tRNA编辑。编辑可以受编辑位点的结构环境的影响，在tRNA的情况下，可以通过文字后修改来调节。在锥形剂中，将TRNA转录在细胞核中，导出到细胞质中，然后将细胞质TRNA的子集积极积极进口到线粒体中。但是，在将TRNA在任何细胞室中启用之前，它们都面临许多酶促反应，包括终端修剪，内含子剪接，tRNA编辑和化学修饰。这些过程中的一些，例如那些在tRNA末端涉及多余序列的过程，通常发生在细胞核中，通常是在细胞质出口之前。其他的，例如编辑和修改，可能会发生在tRNA成熟途径和任何含TRNA的隔室中的任何点。尽管过去几年取得了很多进展，但仍不清楚在分子和细胞水平上如何整合编辑和修饰途径。我们提出，某些生物体可以高度耦合和利用tRNA编辑和修饰事件，以控制tRNA特异性水平的基因表达。这在单细胞真核生物（如锥虫寄生虫）中尤其重要，在该真核生物中，大部分遗传调节都在转录后发生。在该提案中，我们继续研究了T. Brucei的非常独特的tRNA编辑酶，但现在在我们新解决的晶体结构的提示下，我们提出了新的问题，即是什么使该酶如此独特。我们还专注于新发现的一组甲基转移酶，它令人惊讶地针对编辑站点，为我们假设编辑和修饰的相互关系提供了一个奇妙的测试场，以及这种耦合在细胞功能方面的含义。值得注意的是，体外甲基化活性的重建需要添加重组编辑酶的发现，该发现在tRNA编辑和修饰领域中没有先例。作为锥虫（Leishmania和Trypanosoma）中TRNA成熟的基本步骤，这些类型的编辑和修饰事件也为针对具有非常重要的医学重要性的寄生虫提供了非常有吸引力的靶标。鉴于tRNA成熟与疾病之间的联系，这些研究将进一步扩展我们对TRNA作为细胞代谢中心参与者的作用的了解。呢