Mitochondrial translesion DNA synthesis

线粒体跨损伤 DNA 合成

基本信息

批准号：
10587813
负责人：
Yuhui Yin
金额：
$ 38.87万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-04-28 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10587813
关键词：
Active Sites Aging Base Pairing Binding Binding Sites Bioinformatics Biophysics Bypass Cell Aging Cell Nucleus Cells Code Complex Cryoelectron Microscopy Cyclobutanes DNA DNA Primers DNA biosynthesis DNA-Directed DNA Polymerase Dermis Elasticity Electron Transport Energy Metabolism Energy Supply Enzyme Kinetics Enzymes Evolution Exhibits Family Foundations Genes Health Human Introns Investigation Ions Kinetics Knowledge Lesion Location Longevity Maintenance Manganese Mediating Memory Metabolism Metals Methods Mitochondria Mitochondrial DNA Mutation Nuclear Nucleotide Excision Repair Nucleotides Nutrient Organism Oxidative Phosphorylation Oxidative Stress Physiological Polymerase Proliferating Property Proteins Pyrimidine Dimers Role Skin Solid Specific qualifier value Structure Sun Exposure Testing Tissues Ultraviolet Rays Work X-Ray Crystallography biophysical techniques blind dimer genome integrity human disease in vivo insight magnesium ion member mitochondrial genome postmitotic public health relevance repaired replicase response skin disorder stoichiometry ultraviolet damage ultraviolet lesions

项目摘要

ABSTRACT Mitochondrial DNA (mtDNA) integrity is critical for metabolism and cellular energy supply and human health and longevity. Due to lack of repair mechanism and specified translesion synthesis (TLS) polymerase, mtDNA contains higher contents of UV lesions. The high-fidelity mitochondrial DNA polymerase (Pol g) will unavoidably encounter the UV lesions during mtDNA replication. Unlike other high-fidelity DNA polymerases that lack TLS activity, we found Pol g possesses a metal regulated TLS activity. In the presence of magnesium ion, Pol g exhibits no TLS activity, however, in the presence of physiological concentrations of manganese ion alone or Mg/Mn mixture, Pol g can synthesize cross UV lesion cyclobutane dimer with efficiency near that on the non-damaged DNA. We also discovered that Pol g has an extensive lesion recognition network that can sense an upstream lesion as far as 10 base pairs in the presence of Mg2+, but completely ignores the lesion with Mn2+. We hypothesize that Manganese ion can alter the elasticity of Pol g to be able to accommodate bulky lesions for translesion synthesis. we will test the hypothesis by completing the Specific Aims 1) Mechanism of Pol g integrated lesion bypassing, extension, and replication activities, 2) Investigation of Pol g long-range lesion sensing and 3) Biophysical basis for metal-directed Pol g TLS. The proposed studies will illustrate how mitochondrial replicase utilizing the essential metal ions to maintain genome integrity under UV radiation.

抽象的线粒体DNA（mtDNA）完整性对于代谢和细胞能量供应至关重要健康与寿命。由于缺乏修复机制和指定的跨膜合成（TLS）聚合酶， mtDNA包含较高的紫外病变含量。高保真线粒体DNA聚合酶（POL G）将在mtDNA复制过程中，不可避免地会遇到紫外线病变。与其他高保真DNA聚合酶不同缺乏TLS活性，我们发现Pol G具有金属调节的TLS活性。在镁的情况下离子，pol G在存在生理浓度的锰离子的情况下没有TLS活性单独或mg/mn的混合物可以以接近效率的效率合成十字紫外病变环丁烷二聚体未破坏的DNA。我们还发现Pol G具有广泛的病变识别网络，可以感知在MG2+存在下，上游病变至10个碱基对，但完全忽略了MN2+的病变。我们假设锰离子可以改变pol G的弹性，以适应笨重的病变跨性别合成。我们将通过完成具体目的来检验假设1）综合病变绕过，扩展和复制活动，2）调查Pol G远程病变传感和3）金属定向的pol g tls的生物物理基础。拟议的研究将说明如何线粒体复制酶利用必需金属离子在紫外线辐射下维持基因组完整性。