Redox Regulation of Cysteine-Dependent Peroxidases and Signal Transduction Pathways

半胱氨酸依赖性过氧化物酶和信号转导途径的氧化还原调节

• 批准号: 10548745
• 负责人: LESLIE B POOLE
• 金额: $ 38.75万
• 依托单位: WAKE FOREST UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10548745
• 关键词: Acetylation; Active Sites; Aging; Antioxidants; Apoptosis; Area; Biophysics; Cell Cycle Regulation; Cell Signaling Process; Cells; Chemicals; Collaborations; Communicable Diseases; Cysteine; Data; Degenerative Disorder; Development; Disease; Effectiveness; Enzymatic Biochemistry; Enzymes; Eukaryota; Excision; Family; Future; Growth Factor; Health; Hot Spot; Human; Hydrogen Peroxide; Immune system; Impairment; Infectious Agent; Intervention; KRAS2 gene; Malignant Neoplasms; Mediating; Medical; NADPH Oxidase; Organism; Oxidants; Oxidation-Reduction; Paper; Peroxidases; Peroxides; Phosphorylation; Play; Post-Translational Protein Processing; Prevention; Proliferating; Proteins; Publishing; Regulation; Research Personnel; Resistance; Role; Science; Second Messenger Systems; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Source; Structure; Sulfenic Acids; System; TXN gene; Therapeutic Agents; Toxin; Work; combat; cytokine; follow-up; human disease; human pathogen; insight; mutant; nitration; novel therapeutics; oxidation; oxidative damage; peroxiredoxin; receptor internalization; response; spatiotemporal; structural determinants; tool; tumor

SUMMARY While hydrogen peroxide has long been understood as a toxin used by the human immune system to kill infectious organisms, only recently has it become well accepted that it serves as a second messenger in eukaryotes, produced in response to growth factors, cytokines and immune system effectors and promoting or modulating downstream signal transduction pathways. Through insights contributed in part by the work of the PI, a family of cysteine-dependent, peroxide-reducing enzymes known as the peroxiredoxins (Prxs) have also emerged from relative obscurity to become widely recognized not just as one of the primary oxidant removal systems in almost all organisms, but also as key modulators of cell signaling pathways. PI Poole's work on the enzymology, biophysical attributes and structures of Prxs from a variety of organisms has contributed greatly to understanding the mechanism and regulation of this highly abundant family of enzymes. In 2003, PI Poole and collaborator Andy Karplus published a Science paper in which structural determinants of the sensitivity of Prxs toward peroxide-mediated hyperoxidation of the active site cysteine were identified. This led to our proposal of the “floodgate hypothesis” explaining the potential benefits of such a peroxide-mediated “off switch”; under conditions where peroxide levels begin to rise (e.g. NADPH oxidase activation), Prx inactivation would promote the local accumulation of peroxide near the source, allowing for the oxidation of alternative protein targets. Dr. Poole has also been at the forefront of developing chemical tools to evaluate protein oxidation in cells through targeting sulfenic acid (R-SOH), the direct product of peroxide-mediated oxidation. These probes are now commercially available and have been used widely by researchers studying redox regulation and signaling to evaluate protein oxidation with high spatiotemporal precision. PI Poole's lab used these tools to show that cancer-associated growth factors elicit “hot spots” of protein oxidation proximal to the internalized receptors, providing support for the floodgate hypothesis. Future studies proposed here will build upon our existing strengths and collaborations. Specifically, we propose to investigate the effects of additional posttranslational modifications, including nitration, acetylation and phosphorylation, on Prx structure and activity. We will also investigate the mechanism by which thioredoxin can regulate and be regulated by human Prxs. The interface of Prx function with the regulation of signal transduction pathways involving protein oxidation is another area with significant gaps; we plan to follow up on our data suggesting that Prx inactivation and rising peroxide levels are key to cell cycle regulation. Finally, a new area that we are currently investigating in collaboration with Sharon Campbell is the oxidation sensitivity of the cancer-causing G12C mutant of KRAS, which has the potential to severely limit the effectiveness of recently developed therapeutic agents. These efforts will address areas important to Prx function and protein oxidation, leading to a new level of understanding through which medically-and biologically-relevant interventions could be envisioned.

概括 虽然过氧化氢长期以来一直被理解为人类免疫系统使用的毒素 传染性生物，直到最近才被公认为它是第二个使者 真核生物，响应生长因子，细胞因子和免疫系统影响以及促进或 调节下游信号转导途径。通过洞察力部分由 PI是半胱氨酸依赖性的过氧化物再生酶，称为过氧氧蛋白（PRX）也有 从相对晦涩的出现出来，不仅被视为主要氧化剂之一的广泛认可 几乎所有生物的系统，也是细胞信号通路的关键调节剂。皮尔·普尔（Pi Poole）在 来自多种生物的PRX的酶学，生物物理属性和结构已为 了解这种高度丰富的酶家族的机制和调节。 2003年，Pi Poole和 合作者安迪·卡普洛（Andy Karplus）发表了一篇科学论文，其中PRX的敏感性结构决定者 鉴定了朝着过氧化物介导的高氧化型高氧化。这导致了我们的提议 “闸门假设”解释了这种过氧化物介导的“关闭开关”的潜在益处；在下面 过氧化物水平开始升高的疾病（例如NADPH氧化酶激活），PRX失活会促进 过氧化物在源附近的局部积累，允许氧化替代蛋白质靶标。博士 普尔还处于开发化学工具以评估细胞中蛋白质氧化的最前沿 靶向硫酸（R-SOH），这是过氧化物介导的氧化的直接产物。这些问题现在是 商业上可用，研究人员研究了氧化还原调节和信号传导的研究人员已广泛使用 用高时空精度评估蛋白质氧化。 Pi Poole的实验室使用这些工具来表明 癌症相关的生长因子引起了蛋白质氧化的“热点”，靠近内在受体， 为闸门假设提供支持。这里提出的未来研究将基于我们现有的 优势与合作。具体而言，我们建议研究其他翻译后的影响 修改PRX结构和活性，包括硝酸化，乙酰化和磷酸化。我们也会 研究硫氧还蛋白可以通过人PRX调节和调节的机制。接口 通过调节涉及蛋白质氧化的信号转导途径的调节是另一个区域 有明显的差距；我们计划跟进我们的数据，这表明PRX失活和过氧化 水平是细胞周期调节的关键。最后，我们目前正在合作的新领域 与沙龙·坎贝尔（Sharon Campbell 严重限制最近开发的治疗剂的有效性的潜力。这些努力将解决 对PRX功能和蛋白质氧化重要的领域，导致了新的理解水平 可以设想医学和与生物学的干预措施。