Cuproproteins for Redox Biology

用于氧化还原生物学的铜蛋白

基本信息

批准号：
10348180
负责人：
Valeria C Culotta
金额：
$ 41.43万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10348180
关键词：
Active Sites Aerobic Animals Antioxidants Binding Biochemical Biology Biophysics Candida albicans Cells Cellular biology Copper Cu-Superoxide Dismutase Cuprozinc Superoxide Dismutase Enzymes Equilibrium Eukaryota Family Genes Goals Growth Human Hydrogen Peroxide Metabolism Metals Modeling NADPH Oxidase Natural Products Nature Organism Oxidation-Reduction Pathogenesis Pathogenicity Pathway interactions Proteins Reactive Oxygen Species Regenerative capacity Signal Transduction Signaling Molecule Site Solvents Source Superoxide Dismutase Superoxides System Tandem Repeat Sequences Tissues Variant Yeasts antioxidant enzyme cofactor design extracellular fungus pathogen pathogenic fungus polypeptide rho GTP-Binding Proteins structural biology weapons

Active Sites Aerobic Animals Antioxidants Binding Biochemical Biology Biophysics Candida albicans Cells Cellular biology Copper Cu-Superoxide Dismutase Cuprozinc Superoxide Dismutase Enzymes Equilibrium Eukaryota Family Genes Goals Growth Human Hydrogen Peroxide Metabolism Metals Modeling NADPH Oxidase Natural Products Nature Organism Oxidation-Reduction Pathogenesis Pathogenicity Pathway interactions Proteins Reactive Oxygen Species Regenerative capacity Signal Transduction Signaling Molecule Site Solvents Source Superoxide Dismutase Superoxides System Tandem Repeat Sequences Tissues Variant Yeasts antioxidant enzyme cofactor design extracellular fungus pathogen pathogenic fungus polypeptide rho GTP-Binding Proteins structural biology weapons

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项目摘要

All aerobic organisms continuously generate reactive oxygen species (ROS) such as superoxide anion and H2O2 as natural products of metabolism. ROS are potentially damaging to biomolecules, but can also be exploited by cells as weapons for attacking pathogens and as molecules for signaling. To balance the beneficial and potentially harmful effects of ROS, aerobic organisms are armed with a suite of anti-oxidant enzymes, and in eukaryotes, the only enzyme for superoxide is the superoxide dismutase (SOD). SODs use a metal co-factor such as Cu to catalyze at extraordinary rates, the disproportination of superoxide to O2 and H2O2. Until recently, the bimetallic Cu/Zn SOD was believed to be the only Cu SOD for eukaryotes, but in 2014, our lab discovered a new class of SODs that cannot bind Zn and lack sequences to cover the active site, hence, a Cu-only SOD with a highly unusual solvent exposed Cu co-factor. Cu-only SODs are wide-spread throughout the fungal kingdom as the sole extracellular SOD for fungi. In animals, the Cu-only SOD gene underwent twice duplication, resulting in 4x tandem repeats of Cu-only SODs on a single polypeptide we call CSRP (Cu-only SOD repeat protein). What sets the Cu-only SOD family apart from other SODs is their restricted localization and unusual open active site. All Cu-only SODs and CSRP molecules are predicted to be extracellular and remarkably, we find that Cu-only SODs do not acquire their Cu-cofactor from intracellular metal pools, unlike other eukaryotic secreted cuproproteins. Instead, Cu-only SODs are activated outside the cell by extracellular Cu. We hypothesize this new family of cuproproteins evolved to function exclusively outside the cell in extracellular redox biology. Here we combine biophysical, structural biology, and cell biology approaches to examine how the Cu site of Cu-only SODs is fine-tuned to capture Cu and not other metals outside the cell, and how the enzyme functions with extracellular superoxide. In eukaryotes, the primary source of extracellular superoxide is the NADPH oxidase (NOX), typically activated by Rho GTPases to produce ROS for signaling. Recently, we uncovered a surprising NOX - Cu-only SOD partnership in a unicellular fungal pathogen that represents a remarkably simple and unique form of Rho GTPase control of ROS. We will elucidate the mechanism underlying this redumentary system for ROS signaling and define how pathogenic yeasts can use Cu-only SODs and ROS to signal polarized growth. CSRP may likewise function in pathways involving NOX and ROS signaling. Using a vertebrate model, we find CSRP most abundantly expressed in tissues with a high capacity for regeneration by signaling through ROS. Our goals are to uncover the biochemical activities of CSRP and elucidate its function in possible relationship to NOX in tissues with high regenerative capacity. It is remarkable that nature has designed two distinct variations of Cu-containing SODs: the Cu/Zn versus the Cu-only. Our studies promise to uncover how the Cu-only SODs are specialized to operate outside the cell in redox and/or metallobiology.

所有有氧生物均连续产生活性氧（ROS），例如超氧化物阴离子和 H2O2是代谢的天然产物。 ROS可能会损害生物分子，但也可能是被细胞用作攻击病原体的武器和作为信号传导的分子。平衡有益的和潜在的有害作用，有氧生物武装着一套抗氧化剂酶和真核生物中，超氧化物的唯一酶是超氧化物歧化酶（SOD）。草皮使用金属co因子，例如Cu以极大的速率催化，超氧化物对O2和O2和 H2O2。直到最近，双金属Cu/Zn草皮被认为是真核生物的唯一铜草皮，但在 2014年，我们的实验室发现了一类新的草皮，这些草皮无法绑定Zn，并且缺乏序列以覆盖活性站点，因此，仅CU的草皮具有高度不寻常的溶剂裸露Cu cu因子。仅Cu的草皮是广泛的在整个真菌王国中，作为真菌的唯一细胞外草皮。在动物中，仅Cu仅草皮基因进行了两次重复，导致我们称之为单个多肽的仅Cu仅CU的串联重复 CSRP（仅Cu仅SOD重复蛋白）。与其他草皮不同的是什么使仅Cu的草皮家族与众不同的是限制本地化和不寻常的开放活动站点。所有仅CU的SOD和CSRP分子都被预测为是细胞外的，非常明显地，我们发现仅CU的草皮不会从细胞内获取其Cu-cactor 与其他真核生物分泌的蛋白质不同的金属池。相反，仅Cu的草皮在外面激活细胞外铜。我们假设这个新的库蛋白家族已进化为仅发挥作用细胞外氧化还原生物学的细胞外。在这里，我们结合生物物理，结构生物学和细胞生物学检查仅cu仅CU SOD的CU位点以捕获Cu而不是其他金属的方法细胞外，以及酶如何用细胞外超氧化物发挥作用。在真核生物中，主要来源细胞外超氧化物是NADPH氧化酶（NOX），通常由Rho GTPase激活以产生ROS 用于信号。最近，我们发现了一个令人惊讶的NOX-单细胞真菌中的仅Cu -finly SOD伙伴关系病原体代表ROS的Rho GTPase控制的一种非常简单且独特的形式。我们将阐明该冗余系统的ROS信号传导的机制，并定义了致病性酵母菌可以使用仅CU的草皮和ROS来信号极化生长。 CSRP同样可以在途径中发挥作用涉及NOX和ROS信号。使用脊椎动物模型，我们发现CSRP在通过通过ROS发出信号的较高再生能力的组织。我们的目标是发现 CSRP的生化活性，并阐明其在与NOX的可能关系中的功能再生能力。值得注意的是，自然设计了含铜的草皮的两个不同变化： Cu/Zn与仅CU。我们的研究有望揭示如何仅使用CU的草皮专门在氧化还原和/或肠道生物学的细胞外操作。