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：
7263286
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/7263286
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 In Vitro 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 Thinking 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 vivo insight malignant breast neoplasm mutant nervous system disorder pol genes prevent repaired response spleen exonuclease

项目摘要

DESCRIPTION (provided by applicant): 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 DMA repair 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. We will 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 preventing cancer.

描述（由申请人提供）：我们的假设是 TREX1 和 TREX2 是具有 3'-"5' 切除活性的核酸外切酶，对于在 DNA 复制和/或 DMA 修复过程中去除有问题的核苷酸非常重要，我们的目标是研究这些蛋白质目前，TREX1 和 TREX2 被认为是核酸外切酶，因为它们与大肠杆菌 DNA pol 1 大片段和 3 个核酸外切酶序列基序具有同源性。噬菌体 T4 DNA pol 并基于其体外 3'-"5' 核酸外切酶活性。然而，目前还没有更多公开的信息来定义它们的细胞功能。因此，TREX1 和 TREX2 对于维持基因组稳定性甚至癌症预防可能很重要。定义 TREX1 和 TREX2 的三个目标。目标 1：阐明 TREX1 和 TREX2 的基本生化功能。存在三种已知的生化功能：1) 自缔合 2) 核酸外切酶活性，3) 和 DNA 结合活性。我们已经设置了体外测定来观察这些活动，我们的目标是生成受损形式的 TREX1 和 TREX2，它们执行部分但不是全部这些活动。目标 2：通过分析基因改变的小鼠胚胎干 (ES) 细胞来发现 TREX1 和 TREX2 的生物学重要性。我们将比较无效的突变和改变目标 1 中发现的部分但不是全部功能的突变。此时，我们已经生成了 TREX2 无效的 ES 细胞，我们的初步结果表明 TREX2 确实参与了基因组维护。我们发现 TREX2 缺失细胞对某些 DNA 损伤剂表现出敏感性改变，并且 TREX2 缺失细胞表现出基因组不稳定性，包括总体染色体重排。目标 3：分析野生型和 p53 突变背景下的 TREX-null 小鼠。我们将进行寿命分析，并确定与年龄相关的特征（包括癌症和基因组不稳定性）的发病、发生率和范围。 p53 介导的对受损 DNA 的反应的影响将通过研究双突变小鼠来确定。该提案的完成将极大地促进我们对TREX1和TREX2维持基因组稳定性和预防癌症的理解。