Regulation of Nox Enzymes by Calcium and Novel Subunits

钙和新亚基对 Nox 酶的调节

基本信息

批准号：
7239651
负责人：
John David Lambeth
金额：
$ 23.79万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-07-01 至 2009-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7239651
关键词：
4-ethoxymethylene-2-phenyl-2-oxazoline-5-one Alternative Splicing Ants Apoptosis Biochemical Calcium Calcium-Binding Proteins Cancer Cell Growth Cardiovascular Diseases Catalytic Domain Chimeric Proteins Colon Complex Enzyme Activation Enzymes Epithelial Family GTP-Binding Proteins Generations Genus Cola Growth Homologous Gene Hydrogen Peroxide In Vitro Malignant Neoplasms Malignant neoplasm of prostate Messenger RNA Mitosis Molecular Monomeric GTP-Binding Proteins NADP NADPH Oxidase Natural Immunity Oxidases Phagocytes Phosphorylation Play Proline Proline-Rich Domain Protein Isoforms Proteins RNA Splicing Reactive Oxygen Species Regulation Role Signal Transduction Signaling Molecule Site Site-Directed Mutagenesis Testing Testis Tissues angiogenesis base cDNA Library cell type enzyme activity genetic regulatory protein human CYBA protein human SGTA protein in vivo inhibitor/antagonist interest neutrophil cytosol factor 67K novel recoverin protein superoxide-generating NADPH oxidase tumor progression

项目摘要

DESCRIPTION (provided by applicant): We recently described a family of NADP H-oxidases, the Nox enzymes that have been implicated in cancer, particularly colon and prostate cancers. The enzymes are flavocytochromes that produce reactive oxygen species (ROS) and one of these, hydrogen peroxide, has functions as a signal molecule, stimulating mitosis and angiogenesis. Aberrant epithelial expression or activation of these enzymes has therefore been proposed to play a role in cancer progression. However, to date, little is known about how the activity of these enzymes is regulated. This application therefore focuses on the molecular mechanisms of regulation of Nox1, Nox3, Nox4 and Nox5. The Nox enzymes are homologs of gp91phox, the catalytic subunit of the phagocyte respiratory burst oxidase. The latter is regulated by catalytic subunits p47phox and p67phox, and we recently identified novel homologs of these subunits termed NOXO1 (Nox Organizing Protein 1) and NOXA1 (Nox Activating Protein 1) from colon and testis cDNA libraries. Evidence points to these proteins as regulatory subunits of the Noxl and possibly Nox5. We have identified 4 isoforms (splice forms) of NOXO1 and 5 splice forms of NOXAI. In addition, NOXO1 and NOXA1 contain Src-homology 3 (SH3) domains and proline-rich regions, and NOXA1 contains a 4 tandem copies of a TPR motif that is proposed to participate in heterodimer formation with Rac or another small GTP-binding protein. Thus, the role of these subunits and their interaction domains in the regulated assembly/activation of Noxl-5, and the role of small GTPases will be investigated. Nox5 contains a domain similar to the recoverin group of calcium-binding proteins, and is presumed to be regulated by calcium. In addition, Nox5 contains a proline-rich motif that is predicted to interact with an SH3 domain like the one in NOXO1. The role of regulatory subunits and calcium as alternative or synergistic mechanisms for regulating Nox5 will be investigated. These studies are expected to have implications with regard to both normal and aberrant generation of ROS signals relevant to cell growth and cancer.

描述（由申请人提供）：我们最近描述了 NADP 家族 H-氧化酶，即与癌症有关的 Nox 酶，特别是结肠癌和前列腺癌。这些酶是黄素细胞色素，可产生活性氧 (ROS)，其中一种过氧化氢具有信号分子的功能，可刺激有丝分裂和血管生成。因此，这些酶的异常上皮表达或激活被认为在癌症进展中发挥作用。然而，迄今为止，人们对如何调节这些酶的活性知之甚少。因此，本申请重点关注 Nox1、Nox3、Nox4 和 Nox5 调节的分子机制。 Nox 酶是 gp91phox 的同源物，gp91phox 是吞噬细胞呼吸爆发氧化酶的催化亚基。后者受催化亚基 p47phox 和 p67phox 调节，我们最近从结肠和睾丸 cDNA 文库中鉴定了这些亚基的新同源物，称为 NOXO1（Nox 组织蛋白 1）和 NOXA1（Nox 激活蛋白 1）。有证据表明这些蛋白质是 Nox1 的调节亚基，也可能是 Nox5 的调节亚基。我们已经鉴定出 NOXO1 的 4 种亚型（剪接形式）和 NOXAI 的 5 种剪接形式。此外，NOXO1 和 NOXA1 包含 Src 同源 3 (SH3) 结构域和富含脯氨酸的区域，NOXA1 包含 TPR 基序的 4 个串联拷贝，该基序被认为参与与 Rac 或另一种小型 GTP 结合蛋白形成异二聚体。因此，将研究这些亚基及其相互作用结构域在Noxl-5的调节组装/激活中的作用，以及小GTP酶的作用。 Nox5 包含与钙结合蛋白恢复蛋白组相似的结构域，并且推测受到钙的调节。此外，Nox5 包含富含脯氨酸的基序，预计该基序会与 SH3 结构域（如 NOXO1 中的结构域）相互作用。将研究调节亚基和钙作为调节 Nox5 的替代或协同机制的作用。这些研究预计将对与细胞生长和癌症相关的 ROS 信号的正常和异常产生产生影响。