TRANSCRIPTIONAL CONTROL OF MITOCHONDRIAL GENE EXPRESSION IN TRYPANOSOMES

锥虫线粒体基因表达的转录控制

基本信息

批准号：
10641772
负责人：
Ruslan Afasizhev
金额：
$ 41.05万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-13 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10641772
关键词：
Affect Affinity Chromatography Africa South of the Sahara African Animals Area Biological Biotinylation Blood Circulation Chemicals Code Complex DNA DNA biosynthesis DNA-Directed RNA Polymerase Data Developing Countries Development Disease Drug Targeting Economic Burden Elements Eukaryota Evolution Excision Family Foundations Gene Expression Gene Proteins Genes Genetic Transcription Genome Guide RNA Histones Human In Vitro Individual Infection Insecta Kinetoplast DNA Link Location Maps Mass Spectrum Analysis Messenger RNA Mitochondria Mitochondrial DNA Mitochondrial RNA Modeling Molecular Mutation Nucleoproteins Organism Parasites Pathogenesis Phosphorylation Poly A Polyadenylation Polymerase Population Positioning Attribute Proliferating Promoter Regions Proteins Public Health RNA RNA Editing RNA Processing RNA chemical synthesis Recombinants Relaxation Research Resources Ribosomal Proteins Ribosomal RNA Role Shapes Site System TATA Box Taxonomy Transcript Transcription Initiation Transcription Initiation Site Transcriptional Regulation Transfer RNA Trypanosoma Trypanosoma brucei brucei Trypanosomiasis Untranslated RNA crosslink drug development endonuclease experimental study fascinate fungus genome-wide hemoflagellate in vivo innovation insight mRNA Precursor mRNA Transcript Degradation mitochondrial genome particle posttranscriptional promoter protein protein interaction reconstitution respiratory success superresolution microscopy targeted treatment tool transcription factor virtual

项目摘要

ABSTRACT Parasitic protist Trypanosoma brucei causes African human and animal trypanosomiasis, a spectrum of diseases affecting the population and economy in sub-Saharan Africa. These digenetic hemoflagellates belong to Kinetoplastea, a taxonomic class distinguished by possession of a kinetoplast. This nucleoprotein body contains mitochondrial DNA (kDNA) of two kinds: ~25 maxicircles (each ~23 kb) encoding rRNAs, ribosomal proteins and subunits of respiratory complexes, and approximately 5000 of ~1 kb minicircles bearing guide RNA genes. Relaxed maxicircles and minicircles are interlinked and packed into a dense disc-shaped network by association with histone-like proteins. Decades of kDNA studies have unraveled fascinating phenomena of general biological significance, such as DNA bending and mRNA editing, and revealed exquisite details of replication and RNA processing. However, the molecular mechanisms of transcription remain virtually unexplored and arguably constitute the most critical gap in understanding mitochondrial gene expression. The historically enduring view of polycistronic RNA synthesis has abridged efforts to investigate transcription's contribution to regulating genome activity. In contrast, this proposal presents evidence that maxicircle and minicircle genes are individually transcribed into 3′ extended precursors. The transcription start site defines pre-mRNA 5′ terminus, which is subsequently converted into monophosphorylated state by a pyrophosphohydrolase complex, termed the PPsome. Most guide RNAs lack PPsome recognition sites and remain triphosphorylated. Furthermore, we establish that antisense transcripts delimit the 3′ boundaries of mature RNAs by blocking 3′-5′ degradation of precursors by the 3′ processome (MPsome). It follows that transcription start sites on sense and antisense strands define 5′ and 3′ mRNA termini, respectively. These findings support a concept of mitochondrial gene- specific transcriptional control with broad implications in parasite development and pathogenesis. We posit that elucidating transcription complex composition, DNA template requirements and functions of specific factors will build a foundation for this nascent research area. We propose to: 1) Characterize RNA polymerase complex from bloodstream and insect parasite forms, and assess transcription factors' contributions to RNA synthesis; 2) Map maxicircle and minicircle promoters; and 3) Reconstitute the active transcription complex.

抽象的寄生原生生物布氏锥虫引起非洲人类和动物锥虫病，这是一系列疾病影响撒哈拉以南非洲的人口和经济。动质体，一个分类学类别，以拥有动质体为特征。这种核蛋白体包含。两种线粒体 DNA (kDNA)：约 25 个大环（每个约 23 kb），编码 rRNA、核糖体蛋白和呼吸复合体的亚基，以及大约 5000 个带有引导 RNA 基因的约 1 kb 的小环。松弛的大圆和小圆相互连接并通过关联堆积成密集的盘状网络数十年的 kDNA 研究揭示了普通生物学的迷人现象。 DNA弯曲和mRNA编辑等重要意义，以及复制和RNA的精彩精致细节然而，转录的分子机制实际上仍未被探索且存在争议。构成理解线粒体基因表达的最关键差距。多顺反子 RNA 合成的研究减少了研究转录对调节的贡献的努力相比之下，该提议提供了证据表明大环和小环基因是独立的。转录为 3' 延伸前体。转录起始位点定义了前 mRNA 5' 末端。随后通过焦磷酸水解酶复合物转化为单磷酸化状态，称为 PPsome。大多数指导RNA缺乏PPsome识别位点并且保持三磷酸化。确定反义转录物通过阻止 3'-5' 降解来界定成熟 RNA 的 3' 边界 3' 过程组 (MPsome) 的前体序列表明转录起始位点位于有义和反义上。链分别定义了 5' 和 3' mRNA 末端。这些发现支持线粒体基因的概念。我们认为，特定的转录控制对寄生虫的发育和发病机制具有广泛的影响。阐明转录复合体的组成、DNA 模板要求和特定因素的功能将为这一新兴研究领域奠定基础，我们建议：1) 表征 RNA 聚合酶复合物。来自血液和昆虫寄生虫形式，并评估转录因子对 RNA 合成的贡献 2) 绘制大环和小环启动子图；3) 重建活性转录复合物。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A new class of antiparasitic drugs.

DOI：
10.1126/science.adi5925
发表时间：
2023-06-30
期刊：
SCIENCE
影响因子：
56.9
作者：
Aphasizhev, Ruslan;Aphasizheva, Inna
通讯作者：
Aphasizheva, Inna

CryoEM reveals oligomeric isomers of a multienzyme complex and assembly mechanics.

DOI：
10.1016/j.yjsbx.2023.100088
发表时间：
2023
期刊：
JOURNAL OF STRUCTURAL BIOLOGY-X
影响因子：
2.9
作者：
Lee, Jane K. J.;Liu, Yun-Tao;Hu, Jason J.;Aphasizheva, Inna;Aphasizhev, Ruslan;Zhou, Z. Hong
通讯作者：
Zhou, Z. Hong