RNA Polymerase Transcription Past DNA Adducts

RNA 聚合酶转录 DNA 加合物

基本信息

批准号：
7254181
负责人：
David A Scicchitano
金额：
$ 27.86万
依托单位：
NEW YORK UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-30 至 2009-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7254181
关键词：
4-nitroimidazole Active Sites Address Adenine Adopted Affect Area Aromatic Polycyclic Hydrocarbons Base Composition Base Sequence Behavior Benzo(a)pyrene Biochemical Biological Biological Process Biology Bypass Carcinogens Cell Nucleus Cells Characteristics Chemicals Chemistry Chinese Hamster Ovary Cell Cockayne Syndrome Collaborations Complement Complex Computer Simulation Cytosol DNA DNA Adducts DNA Damage DNA Repair DNA Repair Pathway DNA Sequence DNA lesion DNA-Directed DNA Polymerase DNA-Directed RNA Polymerase Data Defect Development Disease Enzymes Epoxy Compounds Event Excision Exhibits Exposure to Frequencies Funding Future Gene Expression Genes Genetic Genetic Transcription Genome Genomics Glycol Goals Grant Growth Guanine Human Joints Kinetics Knowledge Learning Length Lesion Letters Light Literature Messenger RNA Metabolic Clearance Rate Methods Modeling Molecular Molecular Conformation Mutagenesis Mutation New York Nucleotide Excision Repair Nucleotides Oxidoreductase Pathway interactions Patients Pattern Pharmaceutical Preparations Phase Phenotype Play Polymerase Portraits Positioning Attribute Preparation Primer Extension Principal Investigator Property Protein Conformation Proteins Protocols documentation Publishing Purpose Pyrenes RNA RNA Conformation RNA Polymerase II RNA Sequences RNA chemical synthesis RNA primers Range Relative (related person)Reporting Research Research Personnel Ribonucleotides Role Series Shapes Signal Transduction Site Structural Models Structure Study models System T7 RNA polymerase Techniques Testing Title Transcript Transcription Elongation Transcription-Coupled Repair Tumorigenicity Universities Work adduct base benzo(c)phenanthrene benzo(g)chrysene clinical phenotype computer generated falls interest molecular dynamics molecular mechanics molecular modeling prevent professor promoter protein structure pyrene repaired research study size stereochemistry tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): The long range goal of this research is to gain a detailed understanding of how covalently modified bases in DNA affect RNA polymerase behavior during the elongation phase of transcription, with the ultimate objective of producing detailed structural models that portray RNA polymerase interactions at bulky and small adducts found in DNA. The following four Specific Aims will be targeted toward this: (1) to assess the effects of transcription past site-specific lesions on elongation past the damaged or modified site; (2) to determine the base sequence of full-length transcripts, and to characterize the base composition at the 3'- ends of truncated transcripts; (3) to determine Km, and Vrnax values for base addition at DNA adducts during transcription; and (4) to employ computer-modeling techniques to provide characteristics of transcription complexes stalled at DNA adducts. It is now quite clear that certain DNA lesions can cause RNA polymerase to stall at the modified site, resulting in a truncated transcript, or progress past the altered base, producing full-length RNA. Stalled transcription complexes signal transcription-coupled DNA repair. The importance of transcription-coupled DNA repair is evidenced by the clinical phenotype observed when it is aberrant, as is seen in patients with Cockayne's syndrome, a disease characterized by severe growth and developmental defects. There are broad and significant implications for preferential clearance of DNA damage from discrete, active genetic loci: Biases in mutagenesis can exist; correlations of DNA damage and repair with tumorigenesis might be stronger when preferential clearance rates for a particular adduct are used for making the comparisons, rather than total genomic repair; and the actual removal of adducts from the transcribed strand of an expressed gene might be very dependent on their ability to impede RNA synthesis.

描述（由申请人提供）：本研究的长期目标是详细了解 DNA 中共价修饰的碱基如何影响转录延伸阶段的 RNA 聚合酶行为，最终目标是产生描绘 RNA 的详细结构模型DNA 中发现的大加合物和小加合物的聚合酶相互作用。以下四个具体目标将针对此：（1）评估经过特定位点损伤的转录对经过受损或修饰位点的伸长的影响； (2)确定全长转录本的碱基序列，并表征截短转录本3'端的碱基组成； (3)确定转录过程中DNA加合物碱基添加的Km和Vrnax值； (4)采用计算机建模技术来提供停滞在DNA加合物处的转录复合物的特征。现在很清楚，某些 DNA 损伤会导致 RNA 聚合酶在修饰位点停滞，导致转录本被截短，或者超过改变的碱基，产生全长 RNA。停滞的转录复合物发出转录偶联 DNA 修复信号。转录偶联 DNA 修复的重要性可以通过异常时观察到的临床表型得到证明，如在科凯恩综合征患者中所观察到的那样，科凯恩综合征是一种以严重生长和发育缺陷为特征的疾病。从离散的、活跃的基因位点优先清除 DNA 损伤具有广泛而重要的意义：诱变中可能存在偏差；当使用特定加合物的优先清除率而不是总基因组修复进行比较时，DNA损伤和修复与肿瘤发生的相关性可能更强；从表达基因的转录链中实际去除加合物可能很大程度上取决于它们阻碍 RNA 合成的能力。