Mechanisms of Hemoglobin Adaptation to Hypoxia in High-altitude Rodents

高海拔啮齿动物血红蛋白适应缺氧的机制

• 批准号: 7842973
• 负责人: Jay Storz
• 金额: $ 22.08万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7842973
• 关键词: Adopted; Adult; Aerobic; Affect; Affinity; Alleles; Altitude; American; Amino Acids; Animals; Binding; Binding Sites; Biochemical; Biochemistry; Biological Assay; Blood; Blood Substitutes; Bohr effect; California; Cell Respiration; Cells; Characteristics; Chloride Ion; Chronic; Complex; Computer Analysis; Computer Simulation; DNA Sequence; Deer Mouse; Disease Management; Embryo; Environment; Equilibrium; Erythrocytes; Exhibits; Genes; Genetic; Genetic Polymorphism; Genotype; Globin; Goals; Hemeproteins; Hemoglobin; Human; Hypoxia; In Vitro; Individual; Interdisciplinary Study; Ligand Binding; Ligands; Mammals; Measurement; Measures; Messenger RNA; Metabolism; Minor; Modeling; Modification; Molecular; Molecular Analysis; Molecular Evolution; Mus; Mutation; Natural Selections; Nevada; Nitric Oxide; North America; Nucleotides; Oxygen; Pattern; Peromyscus; Pharmaceutical Preparations; Phosphoric Acid Esters; Physiological Adaptation; Population; Population Genetics; Process; Property; Protein Biochemistry; Protein Isoforms; Proteins; Protons; Reactive Oxygen Species; Relative (related person); Research; Research Project Grants; Rodent; Role; Sampling; Sea; Stress; Structure; Surveys; System; Temperature; Testing; Therapeutic; Tissues; Transcript; Transcriptional Regulation; Variant; base; candidate identification; design; diphosphoglycerate; duplicate genes; experimental analysis; gene therapy; genetic analysis; human disease; insight; molecular site; novel; oxygen transport; protein structure function; research study; stoichiometry; structural biology; systems research; theories; tool

The purpose of the proposed research project is to elucidate the molecular basis of physiological adaptation to high-altitude hypoxia, a condition resulting from a reduced supply of oxygen to the cells of respiring tissues. Specifically, the proposed research will involve a structural and functional analysis of hemoglobin variation that is associated with adaptive variation in the blood biochemistry and aerobic metabolism of high-altitude deer mice (Peromyscus maniculatus). Insights into the molecular mechanisms that allow high-altitude animals to survive and function under conditions of chronic hypoxia can aid our understanding and management of disease processes in humans that compromise the oxygen transport system. By identifying the molecular underpinnings of hypoxia tolerance, it may be possible to replicate the mechanism with novel drug-based therapy, gene therapy, and hemoglobin-based blood substitutes. This highly interdisciplinary study will integrate the tools and theory of molecular population genetics, molecular evolution, structural biology, and protein biochemistry. The specific aims of this research project are (1) To identify the specific amino acid mutations that are responsible for hemoglobin adaptation to hypoxia; (2) To assess whether modifications of hemoglobin structure are also associated with regulatory adjustments in the composition stoichiometry of different hemoglobin isoforms in circulating red blood cells; and (3) To assess the functional consequences of the observed structural and regulatory changes. After first conducting a population-level survey of DNA sequence variation to identify naturally occurring mutations in the globin genes of high-altitude deer mice, this study will involve a population-genetic analysis to infer which of the observed amino-acid changes may be attributable to positive Darwinian selection, an analysis of regulatory variation at the mRNA and protein levels, an 'in silico' computational analysis to predict effects on hemoglobin-oxygen affinity, and an 'in vitro' experimental analysis to assess how the identified structural and regulatory changes influence intrinsic oxygen affinity, as well as sensitivities to temperature, protons (Bohr effect), allosteric effectors, and metabolism of reactive oxygen species and nitric oxide. By identifying mechanisms of hemoglobin adaptation that have evolved in natural populations of high-altitude rodents, the proposed research project should provide novel insights into the molecular basis of hypoxia tolerance. Narrative The goal of the proposed research project is to identify the specific changes in hemoglobin function that have evolved in mice that are native to high-altitude environments. By identifying the specific molecular mechanisms that have enabled high-altitude animals to survive and function under low oxygen conditions, it may be possible to replicate the mechanism in therapeutic treatments of human diseases that compromise the oxygen transport system.

拟议的研究项目的目的是阐明 生理适应高海拔低氧，这是由于降低而引起的 向呼吸组织细胞的氧气供应。具体而言，拟议的研究将 涉及相关的血红蛋白变异的结构和功能分析 血液生物化学和高海拔的有氧代谢的自适应变化 鹿小鼠（peromyscus maniculatus）。洞悉分子机制 允许在慢性缺氧条件下生存高海拔动物和功能 可以帮助我们对人类疾病过程的理解和管理 损害氧运输系统。通过识别 低氧耐受性，有可能通过新型药物复制机制 治疗，基因治疗和基于血红蛋白的血液替代物。这很高 跨学科研究将整合分子种群的工具和理论 遗传学，分子进化，结构生物学和蛋白质生物化学。具体 该研究项目的目的是（1）确定特定的氨基酸突变 负责血红蛋白适应缺氧； （2）评估是否 血红蛋白结构的修饰也与调节性调整有关 不同血红蛋白同工型在循环红血中的组成化学计量法 细胞； （3）评估观察到的结构和 监管变化。首次进行DNA序列的人群级调查后 鉴定高海拔球蛋白基因中天然发生的突变的变化 鹿小鼠，这项研究将涉及种群基因分析，以推断哪些 观察到的氨基酸变化可能归因于达尔文阳性的选择，这是一个 分析mRNA和蛋白质水平的调节变异，一个“硅” 计算分析以预测对血红蛋白 - 氧亲和力的影响和“体外” 实验分析以评估确定的结构和调节性变化 影响固有的氧亲和力以及对温度的敏感性，质子（Bohr） 效果），反应性氧和一氧化氮的变构效应子和代谢。 通过识别自然发展的血红蛋白适应机制 拟议的研究项目应提供高海拔啮齿动物的种群 深入了解缺氧耐受性的分子基础。叙述 拟议的研究项目的目的是确定 在本地高空的小鼠中进化的血红蛋白功能 环境。通过识别具有的特定分子机制 使高海拔动物在低氧下生存和功能 条件，可以复制治疗机制 损害氧运输系统的人类疾病的治疗方法。