The Arsenic Stress Signaling Code of Yeast

酵母的砷应激信号编码

基本信息

批准号：
10024658
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
项目类别：
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/10024658
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 Lead MAP Kinase Gene MEKKs MEKs Malignant Neoplasms Mammals Metabolic Metabolic Biotransformation Metabolism Modeling Modification Molecular Nature Osmolar Concentration Osmotic Shocks Output Oxidative Regulation Oxidative Stress Pathway interactions Post-Translational Protein Processing Production Protein Kinase Protein Tyrosine Phosphatase Protein phosphatase Proteins Reactive Oxygen Species Regulation Replication Initiation Role Route 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 ground water inorganic phosphate interest nervous system disorder novel novel strategies protein activation protein function response stress activated protein kinase stressor

项目摘要

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.

项目概要砷是环境中最普遍的毒素。这种天然准金属进入生物圈是从地球化学来源，以及较小程度的人为来源。人体接触砷的量是主要通过食物、水和空气传播，地下水污染构成了世界范围的健康问题。无机砷水溶液主要以三价亚砷酸盐[As(III)]和五价砷酸盐的氧阴离子形式存在 [As(V)]。 As(V) 的毒性比 As(III) 低得多，As(III) 具有硫醇反应性，并与其中的半胱氨酸残基共价结合。蛋白质。长期接触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癌症。建议双方直接 As(III) 和砷产生的活性氧 (ROS) 对生物分子的修饰是造成其毒性和致癌性。尽管存在这些健康影响，As(III) 仍被用作高效的治疗某些类型的癌症。因此，了解动员的细胞反应非常重要由砷引起的应力。 As(V) 和 As(III) 暴露都会刺激酵母应激激活的 MAPK (SAPK) Hog1，其活性对于细胞对砷的反应至关重要。我们对两个一般感兴趣问题。首先，不同的压力源如何激活少量 SAPK？我们发现很多应激源通过细胞内途径激活酵母 SAPK，这些途径以非典型方式与 SAPK 途径相互作用，而不是来自细胞表面的信号传导，这可能会影响 SAPK 的行为。二、如何细胞从激活的 SAPK 中调动连贯的、针对应激的输出？该提案的核心是细胞对砷暴露的反应。我们已经开发出证据表明 As(III) 及其甲基化代谢物 MAs(III) 是重要的信号分子，可让细胞调动保护性、应激特异性通过修饰靶蛋白中的特定半胱氨酸残基来响应。我们称其为砷压力信号代码。 Aim1 扩展了我们最近的发现，即细胞对 As(V) 和 As(III) 的反应不同接触。我们建议了解由这些因素驱动的不同监管事件的机制基础压力源。我们将确定砷修饰的关键靶点以调节甘油通道 Fps1 [As(III) 的主要进入口]，并测试新发现的蛋白质砷修饰的作用参与氧化应激反应和复制启动的调节。目标 2 是了解如何 As(III) 激活的 Hog1 可驱动特定压力的输出。这一目标扩展了我们最近的发现，即 Hog1 本身是被砷修饰，并且这种修饰对于其在 As(III) 响应中的作用很重要。使用质量光谱方法，我们将确定 Hog1 磷酰基响应 As(III) 和 As(V) 并建立 Hog1 靶标特异性是否会因砷化而改变。目标 3 是描绘新途径 As(V) 激活 Hog1 并确定其对于 As(V) 进入细胞的重要性。完成这些目标将建立一个以蛋白质砷化的调控性质为中心的新范式。