Mechanisms and Regulation of Peroxiredoxins

过氧化还原蛋白的机制和调控

基本信息

批准号：
9121765
负责人：
LESLIE B POOLE
金额：
$ 35.92万
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：
2016
资助国家：
美国
起止时间：
2016-04-05 至 2020-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9121765
关键词：
Acetylation Active Sites Address Age-Months Aging Antibiotics Antioxidants Apoptosis Area Attention Biochemical Biological Models Biological Process Biology Calpain Catalysis Cell Differentiation process Cell Signaling Process Cells Chemicals Collection Communicable Diseases Crystallography Cysteine Degenerative Disorder Development Disease Disulfides Drug Targeting Electron Transport Enzymatic Biochemistry Enzymes Equilibrium Eukaryota Explosion Family Goals Growth Health Human Hydrogen Peroxide Immune system Impairment Infectious Agent Influentials Intervention Kinetics Knockout Mice Knowledge Literature Local Anti-Infective Agents Location Malignant Neoplasms Maps Measures Mediating Modeling Modification Molecular Conformation NADPH Oxidase Organism Oxidation-Reduction Oxidative Stress Paper Pathway interactions Peroxidases Peroxides Phosphorylation Phosphotransferases Play Post-Translational Protein Processing Prevention Property Proteins Published Comment Reaction Reducing Agents Regulation Research Role Salmonella typhimurium Science Second Messenger Systems Signal Pathway Signal Transduction Signaling Molecule Site Specificity Structure Surface TXN gene Therapeutic Agents Thermodynamics Time Toll-like receptors Toxin Virulence Factors Work X-Ray Crystallography Xanthomonas campestris base biophysical properties cell growth combat cytokine dimer electron donor human disease improved in vivo inhibitor/antagonist innovation insight killings member microbial nitration novel therapeutics oxidative damage pathogen peroxiredoxin public health relevance second messenger trend ultra high resolution virtual

项目摘要

DESCRIPTION (provided by applicant): Hydrogen peroxide is a toxin used by the human immune system to kill infectious organisms. It is now well accepted that it is also a common second messenger purposefully produced by NADPH oxidases as a part of eukaryotic signaling pathways crucial for human health such as those triggered by cytokines, many growth factors, and toll-like receptors of the innate immune system. Over the past 20 years, in part due to the work of the PIs of this proposal, a distinct, highly abundant family of peroxide-reducing enzymes, peroxiredoxins (Prxs), has gone from relative obscurity to become a major focus of redox biology research. Over these two decades, the PIs have developed expertise in Prx enzymology, biophysical characterization, and structure by characterizing Prxs from various organisms, especially using the peroxiredoxin AhpC of Salmonella typhimurium as a primary model system. Studies of Prxs are important both because Prxs from human pathogens are targets for antibiotic development, and because mammalian Prxs are involved in regulating key signaling pathways, with a Prx1 knockout mouse developing many forms of cancer by nine months of age. In 2003, we discovered that the mobility of protein segments packing near the active site is a key determinant of the sensitivity of Prxs to inactivation by peroxide-mediated hyperoxidation, and we proposed the "floodgate hypothesis" for how this sensitivity to inactivation would benefit organisms, like humans, where hydrogen peroxide is used as a signaling molecule: the antioxidant properties of the Prxs would be switched off at the right times and places to allow for a controlled local accumulation of peroxide. Since that time, additional posttranslational modifications (PTMs) have been shown to regulate the function of human Prxs. Given the importance of Prxs as microbial pathogenicity factors, for combating oxidative stress, and for regulating cell growth and differentiation in human cells, we propose here to address areas of Prx research where the biggest open questions remain. In Aim 1, we will deepen our understanding of key determinants of catalysis and of sensitivity toward hyperoxidation by investigating the biophysical and functional effects of four physiologically relevant PTMs on human Prx activity. In Aim 2, we develop a new Prx `model system' suitable for both NMR and crystallographic studies that will provide an unprecedented ability to measure and correlate dynamic features with structure and function. In Aim 3, we will advance knowledge of the poorly studied, but often rate-limiting, Prx reduction reaction, evaluating for several key Prxs how specificity and efficiency depend on oligomeric state, modification status, and location of a second (resolving) cysteine. We will also map out interaction interfaces by crystallography and/or NMR. These efforts will address areas important to the function and regulation of Prxs which have not yet received sufficient attention in spite of their importance, leading to a new level of understanding through which medically-and biologically-relevant interventions could be envisioned.

描述（由申请人提供）：过氧化氢是人类免疫系统用来杀死传染性生物体的毒素，现在人们普遍认为它也是 NADPH 氧化酶有目的地产生的常见第二信使，作为对真核生物至关重要的信号传导途径的一部分。人类健康，例如由细胞因子、许多生长因子和先天免疫系统的 Toll 样受体引发的健康，部分归功于该领域 PI 的工作。过氧化还原酶 (Prxs) 是一种独特的、高度丰富的过氧化物还原酶家族，在过去的二十年中，PI 已从相对默默无闻成为氧化还原生物学研究的主要焦点，在 Prx 酶学、生物物理表征方面积累了专业知识。和结构，通过表征来自不同生物体的 Prx，特别是使用鼠伤寒沙门氏菌的过氧化还原蛋白 AhpC 作为 Prx 的主要模型系统。之所以重要，是因为来自人类病原体的 Prxs 是抗生素开发的目标，而且因为哺乳动物 Prxs 参与调节关键信号通路，Prx1 敲除小鼠在 9 个月大时会患上多种癌症。 2003 年，我们发现聚集在活性位点附近的蛋白质片段是 Prxs 对过氧化物介导的过度氧化导致的失活敏感性的关键决定因素，我们提出了“闸门假说”来说明这种对失活的敏感性将如何受益像人类这样的有机体，其中过氧化氢被用作信号分子：Prxs 的抗氧化特性将在正确的时间和地点关闭，以允许过氧化物的受控局部积累。从那时起，额外的翻译后修饰（PTM）。 ) 已被证明可以调节人类 Prxs 的功能鉴于 Prxs 作为微生物致病因子、对抗氧化应激以及调节人类细胞生长和分化的重要性，我们在此建议解决以下领域的问题。 Prx 研究中最大的悬而未决的问题仍然存在。在目标 1 中，我们将通过研究四种生理相关 PTM 对人类 Prx 活性的生物物理和功能影响，加深对催化和过度氧化敏感性的关键决定因素的理解。开发适用于核磁共振和晶体学研究的新 Prx“模型系统”，该系统将提供前所未有的测量动态特征并将其与结构和功能相关联的能力。在目标 3 中，我们将增进对研究不足的知识的了解，但通常是限速、Prx 还原反应，评估几个关键的 Prx 的特异性和效率如何取决于寡聚状态、修饰状态和第二个（解析）半胱氨酸的位置。我们还将通过晶体学和/或 NMR 绘制相互作用界面。这些努力将解决对 Prxs 功能和监管重要的领域，尽管这些领域很重要，但尚未得到足够的重视，从而使人们对医学和生物学相关干预措施的理解达到新的水平。