Mechanisms of the 3'-->5' deoxyribonucleases

3-->5 脱氧核糖核酸酶的机制

基本信息

批准号：
7885067
负责人：
FRED W PERRINO
金额：
$ 35.67万
依托单位：
WAKE FOREST UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-03 至 2012-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7885067
关键词：
Active Sites Address Affect Amino Acids Apoptotic Applications Grants Autoimmune Diseases Biochemical Biochemistry Biological Assay Biological Process C-terminal Catalysis Catalytic Domain Cell Death Cell Line Cell Nucleus Cell physiology Cells Cellular Stress Characteristics Chilblains Chromatin Chromatin Disassembly Clinical Complex Coupled DNA DNA Binding Deoxyribonucleases Development Diagnosis Disease Endoplasmic Reticulum Enzymes Escherichia coli Excision Exonuclease Functional disorder Funding Gene Duplication Genes Goals Human Immune System Diseases Individual Laboratories Lupus Mammals Medical Metabolic Pathway Metabolism Molecular Mutation Nature Nuclear Translocation Nucleosomes Nucleotides Outcome Pathway interactions Patients Phenotype Physiological Process Property Proteins Protomer Public Health Research Roentgen Rays Series Structure Symptoms Syndrome System Systemic Lupus Erythematosus TREX1 gene TREX2 gene Testing Transgenic Organisms Variant base dimer gene function insight mutant nuclease research study tool

项目摘要

DESCRIPTION (provided by applicant): The 3'??5' deoxyribonucleases are essential enzymes in DNA metabolism that catalyze excision of nucleotides from the 3' ends of DNA to prepare these 3' termini for subsequent steps during DNA processing. The long term goal of this project is to understand the biochemistry of the 3'??5' deoxyribonucleases encoded by the TREX genes that function in human cells and to elucidate the DNA metabolic pathways in which these enzymes function. The existence of 3' deoxyribonucleases in human cells has been recognized for almost forty years, but the biological functions of these enzymes are not well described. In the previous funding period we determined the structures of the TREX1 and TREX2 enzymes allowing us to begin to describe the biochemical properties of these 3' deoxyribonucleases. The TREX1 and TREX2 genes encode two structurally similar dimeric 3' deoxyribonucleases. The TREX1 enzyme contains a C-terminal region that is not found in TREX2, and the presence of two TREX genes is only found in mammals. Our biochemical studies to define the precise molecular characteristics of TREX1 have allowed us to quantify the activities of mutant TREX1 enzymes identified in patients diagnosed with the autoimmune diseases Aicardi- Goutieres syndrome, familial chilblain lupus, and in some cases of systemic lupus erythematosus. The finding of TREX1 mutations in autoimmune disease patients parallels the finding of TREX1 participation in apoptotic cell death. In this competitive renewal we will utilize the molecular tools we have developed in the previous funding period to focus our studies on the mechanisms of TREX1 action within cell death pathways. These studies will further our understanding of TREX1 exonuclease processing of DNA in cells by identifying the physiological substrate of TREX1 and will inform us of the mechanisms of TREX1 dysfunction that cause the pathological findings associated with autoimmune disease. Our efforts to understand the mechanisms of TREX1 biochemistry and cellular function are addressed according to the following aims. In Aim 1 we will determine the mechanism of TREX1 action within the catalytic core. In Aim 2, we will determine the effects of TREX1 on chromatin disassembly in cell death pathways. In Aim 3 we will determine the mechanism of TREX1 targeting to the ER. PUBLIC HEALTH REVELANCE: This grant proposal is to study how enzymes process DNA and to determine how dysfunction of these enzymes causes autoimmune disease. The outcome of the proposed research will have a significant impact on the medical treatment of complex autoimmune diseases such as systemic lupus erythematosus.

描述（由申请人提供）： 3'→5'脱氧核糖核酸酶是DNA代谢中必需的酶，其催化DNA 3'末端的核苷酸切除，为DNA加工过程中的后续步骤准备这些3'末端。该项目的长期目标是了解在人类细胞中发挥作用的 TREX 基因编码的 3'5' 脱氧核糖核酸酶的生物化学，并阐明这些酶发挥作用的 DNA 代谢途径。人类细胞中 3' 脱氧核糖核酸酶的存在已被认识了近四十年，但这些酶的生物学功能尚未得到很好的描述。在之前的资助期间，我们确定了 TREX1 和 TREX2 酶的结构，使我们能够开始描述这些 3' 脱氧核糖核酸酶的生化特性。 TREX1 和 TREX2 基因编码两种结构相似的二聚体 3' 脱氧核糖核酸酶。 TREX1酶含有TREX2中没有的C末端区域，并且两个TREX基因的存在仅在哺乳动物中发现。我们对 TREX1 精确分子特征的生化研究使我们能够量化在诊断患有自身免疫性疾病 Aicardi-Goutieres 综合征、家族性冻疮狼疮以及某些系统性红斑狼疮患者中发现的突变 TREX1 酶的活性。在自身免疫性疾病患者中发现的 TREX1 突变与 TREX1 参与细胞凋亡的发现相似。在这次竞争性更新中，我们将利用我们在上一个资助期开发的分子工具，将我们的研究重点放在TREX1在细胞死亡途径中的作用机制上。这些研究将通过鉴定 TREX1 的生理底物，进一步加深我们对细胞中 DNA 的 TREX1 核酸外切酶加工的理解，并将告知我们 TREX1 功能障碍导致与自身免疫性疾病相关的病理结果的机制。我们为了解 TREX1 生物化学和细胞功能机制所做的努力是根据以下目标进行的。在目标 1 中，我们将确定 TREX1 在催化核心内的作用机制。在目标 2 中，我们将确定 TREX1 对细胞死亡途径中染色质分解的影响。在目标 3 中，我们将确定 TREX1 靶向 ER 的机制。公众健康启示：这项拨款提案旨在研究酶如何处理 DNA 并确定这些酶的功能障碍如何导致自身免疫性疾病。的结果拟议的研究将对系统性红斑狼疮等复杂自身免疫性疾病的医学治疗产生重大影响。