The Arsenic Stress Signaling Code of Yeast

酵母的砷应激信号编码

• 批准号: 10632034
• 负责人: DAVID E. LEVIN
• 金额: $ 43.89万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10632034
• 关键词: Air; Arsenates; Arsenic; Arsenicals; Arsenites; Binding; Biochemical; Cardiovascular Diseases; Cell membrane; Cell surface; Cells; Cellular Metabolic Process; Chronic; Code; Cysteine; Diabetes Mellitus; Disease; Environment; Enzymes; Event; Evolution; Exposure to; Food; Food Contamination; Genetic; Glycerol; Health; Hypertension; Iron; MAP Kinase Gene; MEKKs; MEKs; Malignant Neoplasms; Mammals; Metabolic; Metabolic Biotransformation; Metabolism; Methylation; Modeling; Modification; Molecular; Nature; Osmolar Concentration; Output; Oxidative Regulation; Oxidative Stress; Pathway interactions; Post-Translational Protein Processing; Production; Protein Kinase; Protein Tyrosine Phosphatase; Protein phosphatase; Proteins; Reaction; Reactive Oxygen Species; Regulation; Replication Initiation; Role; Route; Shock; Signal Transduction; Signaling Molecule; Source; Specificity; Stress; Substrate Specificity; Sulfhydryl Compounds; Testing; Toxic effect; Toxin; Tyrosine; Water; Yeasts; anthropogenesis; aqueous; base; behavior influence; biological adaptation to stress; cancer therapy; cancer type; carcinogenicity; cell behavior; chemotherapeutic agent; effective therapy; exposed human population; geochemistry; ground water; inorganic phosphate; interest; nervous system disorder; novel; novel strategies; protein activation; protein function; response; stress activated protein kinase; stressor

Project Summary Arsenic is the most prevalent toxin in the environment. This natural metalloid enters the biosphere from geochemical sources and, to a lesser degree, from anthropogenic sources. Human exposure to arsenic is mainly through food, water and air, and contamination of groundwater poses a worldwide health problem. Inorganic aqueous arsenic exists mainly as oxyanions of trivalent arsenite [As(III)] and pentavalent arsenate [As(V)]. As(V) is much less toxic than As(III), which is thiol reactive and binds covalently to cysteine residues in proteins. Chronic exposure to inorganic arsenic is associated with cardiovascular disease and hypertension, diabetes mellitus, neurological disorders, and various forms of cancer. It has been proposed that both direct modification of biomolecules by As(III) and reactive oxygen species (ROS) generated by arsenicals are responsible for its toxicity and carcinogenicity. Despite these health effects, As(III) is used as a highly effective treatment for certain types of cancers. Therefore, it is important to understand the cellular responses mobilized by arsenic-induced stress. Both As(V) and As(III) exposure stimulate the yeast stress-activated MAPK (SAPK) Hog1, whose activity is critically important for the cellular response to arsenic. We are interested in two general questions. First, how do diverse stressors activate a small number of SAPKs? We have found that many stressors activate yeast SAPKs by intracellular routes that interface with SAPK pathways in atypical ways, rather than signaling from the cell surface, which may influence the behavior of the SAPK. Second, how does the cell mobilize coherent, stress-specific outputs from an activated SAPK? This proposal centers on the cellular responses to arsenic exposure. We have developed evidence that both As(III) and its methylated metabolite, MAs(III), are important signaling molecules that allow cells to mobilize protective, stress-specific responses through modification of specific cysteine residues in target proteins. We refer to this as an arsenic stress signaling code. Aim1 extends our recent findings that cells respond differently to As(V) and As(III) exposure. We propose to understand the mechanistic bases of distinct regulatory events driven by these stressors. We will identify key targets of arsenic modification for the regulation of the glycerol channel Fps1 [the major port of entry for As(III)], and test the role of newly discovered arsenic modifications of proteins involved in the regulation of the oxidative stress response and replication initiation. Aim 2 is to understand how Hog1 activated by As(III) drives stress-specific outputs. This aim extends our recent finding that Hog1 itself is modified by arsenic and that this modification is important for its role in the response to As(III). Using mass spectral approaches, we will determine the Hog1 phosphorylome in response to As(III) and As(V) and establish whether Hog1 target specificity is altered by arsenylation. Aim 3 is to delineate the novel pathway by which As(V) activates Hog1 and to determine its significance for As(V) entry to cells. Completion of these aims will establish a novel paradigm centered on the regulatory nature of protein arsenylation.

项目摘要 砷是环境中最普遍的毒素。这种天然金属从 地球化学来源，并且在较小程度上是从人为来源的。人类接触砷的是 主要通过食物，水和空气以及地下水的污染构成了全球健康问题。 无机水溶液主要作为三价砷的氧[AS（iii）和五芳族砷的氧气存在 [AS（v）]。 AS（V）的毒性比（III）低得多，该毒性是硫醇反应性的，与半胱氨酸残基结合在 蛋白质。长期暴露于无机砷与心血管疾病和高血压有关， 糖尿病，神经系统疾病和各种形式的癌症。有人提出，两者都直接 AS（III）和活性氧（ROS）对生物分子的修饰为 负责其毒性和致癌性。尽管有这些健康影响，AS（iii）被用作高效 治疗某些类型的癌症。因此，了解动员的细胞反应很重要 通过砷引起的应力。 AS（V）和（III）暴露都刺激了酵母应激激活的MAPK（SAPK） HOG1，其活性对于对砷的细胞反应至关重要。我们对两个将军感兴趣 问题。首先，不同的压力源如何激活少数SAPK？我们发现很多 压力源通过以非典型方式与SAPK途径接口的细胞内路线激活酵母SAPK， 而不是从细胞表面发出信号，这可能会影响SAPK的行为。第二，怎么样 细胞动员了来自活化的SAPK的相干，应力特异性输出？该提议以 细胞对砷暴露的反应。我们已经建立了证据表明（iii）及其甲基化的证据 代谢产物，MAS（III）是重要的信号分子，可使细胞动员保护性，应力特异性 通过修饰靶蛋白中特定半胱氨酸残基的反应。我们将其称为砷 压力信号代码。 AIM1扩展了我们最近的发现，即细胞对（v）和（iii）的反应不同。 接触。我们建议了解这些驱动的不同监管事件的机械基础 压力源。我们将确定砷修饰的关键目标，以调节甘油通道FPS1 [AS（iii）的主要进入港口]，并测试新发现的蛋白质修饰的作用 参与调节氧化应激反应和复制起始。目标2是了解如何 由AS激活的HOG1驱动应力特异性输出。这个目标扩展了我们最近的发现，Hog1本身是 通过砷进行修改，这种修饰对于其在对AS（III）的响应中的作用很重要。使用质量 光谱方法，我们将根据AS（III）和AS（V）确定HOG1磷酸浓度 HOG1靶标特异性是否通过砷化而改变。 AIM 3是描绘新的途径 AS（V）激活HOG1并确定其对（V）进入细胞的重要性。这些目标的完成将 建立一个以蛋白质砷化的调节性质为中心的新型范式。