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Mechanisms of DNA and RNA Transactions

DNA 和 RNA 交易的机制

基本信息

批准号：
10618537
负责人：
Stewart H Shuman
金额：
$ 108.32万
依托单位：
SLOAN-KETTERING INST CAN RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-05-03 至 2028-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10618537
关键词：
Antifungal Agents Archaea Bacteria Bacteriophage T4 Biochemistry Biological Models Cell physiology Cells Cellular Stress Code Complex DNA Diphosphates Enzymes Event Family Fission Yeast Functional disorder Gene Expression Gene Expression Regulation Genetic Genetic Transcription Goals Guanosine Triphosphate Homeostasis Human Human Genome Immune response Inositol Ligase Mediating Messenger RNA Microbiology Modification Mycoses Normal Cell Nucleic Acids Nucleotides Pathway interactions Phosphotransferases Phylogenetic Analysis Physiology Proteins RNA RNA Ligase (ATP)RNA Splicing Reaction Regulation Regulon Repression Research Retrotransposition Signaling Molecule Specificity Structure System TPT1 gene Transfer RNA Virus Virus Diseases cofactor drug discovery enzyme structure fungus gene repression inorganic phosphate promoter pyrophosphatase repair enzyme repaired response structural biology tRNA Ligase tool transcription termination

项目摘要

PROJECT SUMMARY: The goals of the research proposed for the MIRA renewal are: (i) to understand the mechanisms and structures of enzymes that perform nucleic acid synthesis, modification, and repair; and (ii) to elucidate factors that regulate these events. The project integrates diverse experimental approaches (microbiology, biochemistry, structural biology, genetics) and applies them to model systems ranging from viruses to bacteria to fungi. The principal themes are: (1) The structures, mechanisms, and distinctive specificities of fungal tRNA splicing enzymes Trl1 (tRNA ligase) and Tpt1 (tRNA 2'-phosphotransferase) – as paradigms of an RNA repair system essential for normal cell physiology and as promising targets for anti-fungal drug discovery. We will determine structures of Trl1 and Tpt1 in complexes with nucleic acid and nucleotide substrates and cofactors, and endeavor to capture structural snapshots of intermediates and transition-states along the reaction pathways. (2) The structural basis for RNA recognition and strand joining by ATP-dependent 5'-PO4/3'-OH RNA ligase T4 Rnl1. Rnl1 is a tRNA repair enzyme that the T4 bacteriophage uses to evade a tRNA-damaging host response to virus infection. (3) The unique catalytic mechanism, end-specificity, and regulation of GTP-dependent 3'-PO4/5'-OH RNA ligase RtcB. The RtcB-family ligases are found in all phylogenetic domains. They are agents of diverse RNA transactions, including tRNA splicing (in metazoa and archaea), RNA repair (in bacteria), nonspliceosomal mRNA splicing (in the metazoan unfolded protein response), and the formation of chimeric RNAs in human cells that can undergo retrotransposition into the human genome. (4) Tandem transcriptional interference as a controlling factor in fission yeast phosphate homeostasis. The three S. pombe PHO regulon genes are repressed in phosphate-replete cells by transcription in cis of 5’- flanking lncRNAs that interferes with the PHO mRNA promoters. The lncRNA-mediated interference that underlies the repression of pho1 has afforded us a sensitive read-out of genetic influences on 3'- processing/termination and a powerful tool for discovery of agents and regulators of this step of the Pol2 transcription cycle. These influences include: (i) the Pol2 CTD code; (ii) numerous components of the 3'- processing/termination machinery; and (iii) metabolite control by inositol pyrophosphate 1,5-IP8, an intracellular signaling molecule. We propose to investigate the fission yeast Asp1 kinase/pyrophosphatase enzyme that determines IP8 dynamics and the cellular proteins and pathways that connect IP8 to gene expression.

项目总结：MIRA更新的研究目标是：(i)了解