Regulation of Nox Enzymes by Calcium and Novel Subunits

钙和新亚基对 Nox 酶的调节

• 批准号: 8066381
• 负责人: John David Lambeth
• 金额: $ 24.55万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8066381
• 关键词: Adult Respiratory Distress Syndrome; Arthritis; Atherosclerosis; Binding; Binding Sites; Biological Process; Calcium; Cardiovascular Diseases; Catalytic Domain; Cell model; Cell physiology; Cells; Cirrhosis; Co-Immunoprecipitations; Data; Diabetes Mellitus; Diabetic Nephropathy; Dimerization; Disease; Disease Progression; Distal; Dominant-Negative Mutation; EF-Hand Domain; Electrons; Enzymes; Fibrosis; Fluorescence Polarization; Free Radicals; Generations; Gravity Perception; Growth Disorders; Heme; Homology Modeling; Hormones; Human; Hypertension; Infection; Inflammatory; Isoenzymes; Leukocytes; Liver Cirrhosis; Lung; Malignant Neoplasms; Mediating; Membrane; Modeling; Molecular; Molecular Conformation; Mutation; Myocardial Infarction; NADP; Natural Immunity; Nox enzyme; Organ Transplantation; Oxidoreductase; Peptides; Pharmaceutical Preparations; Physiology; Play; Process; Production; Protein Isoforms; Protein Region; Publishing; Pulmonary Fibrosis; Radiation; Reactive Oxygen Species; Regulation; Reperfusion Injury; Role; Side; Signal Transduction; Stroke; Structural Models; Surface; Testing; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Tissues; Transmembrane Domain; cancer complication; cell type; design; dimer; fighting; gel electrophoresis; interfacial; monomer; neutrophil cytosol factor 67K; novel; prevent; public health relevance; research study; superoxide-generating NADPH oxidase; synthetic peptide

DESCRIPTION (provided by applicant): Nox/Duox enzymes - NADPH-oxidases that generate superoxide and secondary reactive oxygen species (ROS) - participate in normal physiology including cell signaling, innate immunity, thyroid hormone synthesis, and gravity perception. Over-production of ROS by these enzymes is associated with molecular damage and aberrant signaling in disease classes such as hyperproliferative disorders (e.g., cancer, hypertension, atherosclerosis), fibrotic disease (pulmonary fibrosis, cirrhosis, diabetic nephropathy), inflammatory disorders (ARDS, arthritis, atherosclerosis), and reperfusion injury (stroke, myocardial infarction, organ transplantation). The seven human Nox isoenzymes reflect three modes of regulation: 1) constitutively active (Nox4); 2) activation by assembly with regulatory subunits (Nox1, Nox2 and Nox3); and 3) calcium-activated (Nox5, Duox1 and Duox2). We will study the molecular mechanisms of regulation of the catalytic subunits, using Nox2 as representative of subunit-regulated Noxes, Nox4 as a constitutively active Nox, and Nox5 as a Ca2+regulated Nox. The underlying hypothesis to be explored is that all three activation mechanisms induce the same active conformation in the catalytic moiety, allowing electron flow from NADPH to form ROS. Regions on the catalytic subunit involved in responding to calcium or subunits will be identified and characterized, and information will be integrated using a newly developed homology structural model of the Nox catalytic subunit. We will explore the possibility of catalytically essential dimerization, and will investigate the roles of key conserved protein regions identified by an evolutionary comparison of more than 100 Nox enzymes in multiple species. A molecular understanding of the regulation of Nox/Duox enzymes will provide key information that will be key to preventing excess or inappropriate ROS generation and mitigating the course of these diseases. PUBLIC HEALTH RELEVANCE: Nox/Duox enzymes generate a form of free radical referred to as reactive oxygen species (ROS), which is used in normal biological processes to regulate many types of cells and to play a role in the ability of white blood cells to fight infections, the thyroid to produce hormones, and many other normal functions. However, in disease, overproduction of ROS by these enzymes causes both tissue damage and abnormalities in basic cellular functions, and plays a key role in some cancers, complications of diabetes, stroke, cardiovascular diseases, and many other diseases. In order to prevent the progression of these diseases, it is essential to understand the molecular changes that turn on these enzymes to produce too much ROS. This proposal centers on understanding the fundamentals of this process, and has direct implications, for example in our ability to design new classes of drugs that treat these diseases by targeting Nox/Duox enzymes.

描述（由申请人提供）：Nox/Duox 酶 - 产生超氧化物和次级活性氧 (ROS) 的 NADPH 氧化酶 - 参与正常生理学，包括细胞信号传导、先天免疫、甲状腺激素合成和重力感知。这些酶过量产生 ROS 与疾病类别中的分子损伤和异常信号传导有关，例如过度增殖性疾病（例如癌症、高血压、动脉粥样硬化）、纤维化疾病（肺纤维化、肝硬化、糖尿病肾病）、炎症性疾病（ARDS、关节炎、动脉粥样硬化）和再灌注损伤（中风、 心肌梗死、器官移植）。七种人类 Nox 同工酶反映了三种调节模式：1）组成型活性（Nox4）； 2) 通过与调节亚基（Nox1、Nox2 和 Nox3）组装来激活； 3) 钙激活（Nox5、Duox1 和 Duox2）。我们将研究催化亚基调节的分子机制，以Nox2作为亚基调节的Nox的代表，Nox4作为组成型活性的Nox，Nox5作为Ca2+调节的Nox。有待探索的基本假设是，所有三种激活机制都会在催化部分中诱导相同的活性构象，从而允许电子从 NADPH 流到形成 ROS。催化亚基上涉及钙或亚基响应的区域将被识别和表征，并且将使用新开发的 Nox 催化亚基同源结构模型来整合信息。我们将探索催化必需二聚化的可能性，并将研究通过对多个物种中 100 多种 Nox 酶进行进化比较而确定的关键保守蛋白质区域的作用。对 Nox/Duox 酶调节的分子理解将提供关键信息，这些信息对于防止过量或不适当的 ROS 生成以及减轻这些疾病的进程至关重要。 公共健康相关性：Nox/Duox 酶会产生一种称为活性氧 (ROS) 的自由基，它在正常生物过程中用于调节多种类型的细胞，并在白细胞抵抗感染的能力、甲状腺产生激素的能力以及许多其他正常功能中发挥作用。然而，在疾病中，这些酶过量产生ROS会导致组织损伤和基本细胞功能异常，并在一些癌症、糖尿病并发症、中风、心血管疾病和许多其他疾病中发挥关键作用。为了防止这些疾病的进展，有必要了解导致这些酶产生过多 ROS 的分子变化。该提案的重点是了解这一过程的基本原理，并具有直接影响，例如，我们有能力设计通过靶向 Nox/Duox 酶来治疗这些疾病的新型药物。