Discovering TREX1 and TREX2 Function in Mammalian Cells and Mice

发现哺乳动物细胞和小鼠中的 TREX1 和 TREX2 功能

基本信息

批准号：
7754073
负责人：
EDWARD PAUL HASTY
金额：
$ 27.74万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-04-01 至 2012-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7754073
关键词：
Address Aging Amino Acids BRCA2 gene Bacteriophage T4 Biochemical Biological Biological Process Cell physiology Cells Characteristics Chromosomal Rearrangement Colorectal Cancer DNA DNA Binding DNA Damage DNA Double Strand Break DNA Repair DNA biosynthesis Data Defect Escherichia coli Excision Exhibits Exonuclease Genetic Genome Genome Stability Genomic Instability Goals Homologous Protein Human Incidence Knockout Mice Longevity MSH2 gene Maintenance Malignant Neoplasms Mammalian Cell Mediating Mismatch Repair Mus Mutant Strains Mice Mutate Mutation Nucleotides Null Lymphocytes Phenotype Phosphodiesterase I Physiological Proteins Publishing Robertsonian Translocation Small Interfering RNA Structure-Activity Relationship TP53 gene TREX1 gene TREX2 gene Testing Time Tumor Suppressor Proteins Yeasts age related base cancer genomics cancer prevention cancer risk crosslink embryonic stem cell homologous recombination improved in vitro Assay in vitro activity in vivo insight malignant breast neoplasm mutant nervous system disorder repaired response spleen exonuclease

项目摘要

Our hypothesis is that TREX1 and TREX2 are exonucleases with 3'-¿5' excision activity that is important for removing problematic nucleotides during either DNA replication and/or DMArepair and our goal is to study these proteins in cells and mice. Currently TREX1 and TREX2 are thought to be exonucleases based on their homology to three exonuclease sequence motifs of E. coli DNA pol 1 large fragment and bacteriophage T4 DNA pol and based on their 3'-¿5' exonuclease activity in vitro. However, at this time there is no more published information defining their cellular function. Thus, TREX1 and TREX2 are potentially important for maintaining genomic stability and perhaps cancer prevention. There are three aims that define TREX1 and TREX2. Aim 1: to elucidate fundamental TREX1 and TREX2 biochemical functions. There three known biochemical functions: 1) self association 2) exonuclease activity, 3) and DNA binding activity. We have setup in vitro assays to observe these activities and our goal is to generate impaired forms of TREX1 and TREX2 that perform some but not all of these activities. Aim 2: to discover the biological importance of TREX1 and TREX2 by analyzing genetically altered mouse embryonic stem (ES) cells. We will compare a mutation that is null to mutations that alter some but not all functions as discovered in aim 1. At this time we have generated TREX2-null ES cells and our preliminary results demonstrate that TREX2 is indeed involved in genome maintenance. We show TREX2-null cells exhibit altered sensitivity to some DNA damaging agents and TREX2-null cells exhibit genomic instability including gross chromosomal rearrangements. Aim 3: to analyze TREX-null mice in wild type and p53 mutant backgrounds. Wewill perform a life span analysis and determine the onset, incidence and spectra of age-related characteristics including cancer and genomic instability. The impact p53-mediated responses to damaged DNA will be determined by studying double-mutant mice. Completion of this proposal will greatly facilitate our understanding of TREX1 and TREX2 for maintaining genome stability and for preventingcancer.

我们的假设是TREX1和TREX2是具有3'-- 5'满意活动的外切核酸酶对于在DNA复制和/或DMAREPAIR期间去除问题的核苷酸以及我们的目标是研究细胞和小鼠中的这些蛋白质。当前TREX1和TREX2被认为是除外切的核酸酶基于其与大肠杆菌DNA POL 1的三个核酸外切酶序列基序的同源性大片段和噬菌体T4 DNA POL，并基于其3'- - 5'外切核酸酶活性。但是，目前没有更多的发布信息来定义其细胞功能。那， TREX1和TREX2对于维持基因组稳定性可能很重要，也许可能取消预防。有三个定义TREX1和TREX2的目标。目标1：阐明基本 TREX1和TREX2生化功能。有三个已知的生化功能：1）自我关联2）外切核酸酶活性，3）和DNA结合活性。我们已经进行了体外测定观察这些活动，我们的目标是产生trex1和trex2的受损形式执行一些但不是全部这些活动。目标2：发现Trex1的生物学重要性和TREX2通过分析的一般改变的小鼠胚胎（ES）细胞。我们将比较一个突变对突变发生了变化，而突变改变了AIM 1中发现的某些功能但并非所有功能。我们已经生成了Trex2-null ES细胞，我们的初步结果表明TREX2是确实参与了基因组维持。我们显示Trex2-null细胞暴露于对一些DNA破坏剂和Trex2-Null细胞暴露了基因组不稳定性，包括总染色体重排。目标3：分析野生型和p53突变体的Trex-null小鼠背景。我们将进行寿命分析并确定的发作，事件和光谱与年龄有关的特征，包括癌症和基因组不稳定性。撞击p53介导对受损DNA的反应将通过研究双突变小鼠来确定。完成此操作提案将极大地促进我们对TREX1和TREX2的理解，以维持基因组稳定性和预防范围。