Molecular Mechanisms of Signal Transduction by Two-Component Regulatory Systems

二元调控系统信号转导的分子机制

• 批准号: 8233800
• 负责人: Robert B. Bourret
• 金额: $ 43.54万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8233800
• 关键词: Accounting; Active Sites; Affect; Affinity; Amino Acid Sequence; Amino Acids; Animals; Antibiotics; Archaea; Architecture; Bacteria; Bacterial Antibiotic Resistance; Behavior; Binding; Biochemical; Biochemistry; Bioinformatics; Biological; Biological Assay; Biological Process; Biophysics; Cataloging; Catalogs; Catalysis; Cells; Characteristics; Data; Development; Diabetes Mellitus; Disease; Elements; Engineering; Environment; Eukaryota; Exhibits; Genetic; Genetic Variation; Genomics; Goals; Grant; Growth; Health; Human; Imagery; Infection; Investigation; Ions; Kinetics; Lead; Learning; Life; Malignant Neoplasms; Measures; Mediating; Metals; Microbe; Molecular; Molecular Biology; Monitor; Nature; Output; Peptide Sequence Determination; Pharmaceutical Preparations; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Phylogenetic Analysis; Physiology; Plants; Predisposition; Prokaryotic Cells; Property; Protein Dephosphorylation; Proteins; Reaction; Regulation; Research; Signal Transduction; Signaling Protein; Site-Directed Mutagenesis; Specificity; Speed; Staging; Stimulus; Structure; System; Testing; Therapeutic Agents; Time; Titrations; Virulence; Water; Work; X-Ray Crystallography; bacterial resistance; biological information processing; cell growth; computerized data processing; design; experience; genome sequencing; innovation; interest; killings; microbial; microorganism; pathogen; reaction rate; research study; response; sensor; small molecule; structural biology; success

DESCRIPTION (provided by applicant): The ability to respond to stimuli is often considered to be a key characteristic of life. Cells can detect new conditions, transduce that information into a usable form, and execute an appropriate response. One common signal transduction strategy is to represent information by the specific and transient placement of phosphoryl groups on proteins. Errors in signal transduction can lead to diseases (e.g. cancer, diabetes), and drugs have been developed to block aberrant signaling processes. Understanding the mechanisms, regulation, and impact of protein phosphorylation is thus of fundamental interest, as well as of practical significance to human health. Microorganisms are the dominant form of life on Earth by many measures, including genetic diversity, raw numbers, environmental distribution, and evolutionary experience. Thus, it is logical to seek basic signal transduction principles in microbes. Our long-term goal is comprehensive understanding of signal transduction by two-component regulatory systems, which occur in microorganisms from all three phylogenetic domains. In a typical two-component system, a sensor kinase detects stimuli and autophosphorylates. A response regulator then catalyzes phosphorylation from the sensor kinase (or from small molecules), which turns on the response. Response regulator dephosphorylation, either self-catalyzed or mediated by a phosphatase, ends the response. The kinetics of phosphoryl group reactions are important to synchronize responses with stimuli. Genome sequencing presents a challenge (a rapidly widening gap between the number of known proteins and what can be studied) and an opportunity (diverse and extensive sequence data). To learn how to reveal properties of tens of thousands of two-component proteins from sequence data alone, our innovative research strategy focuses on sequence differences (rather than similarities) between the conserved domains of sensor kinases or response regulators. We were productive during the previous grant period with an approach that integrated biochemistry, bioinformatics, biophysics, genetics, molecular biology, and structural biology. We identified factors that greatly affect response regulator reaction rates, but do not account for the entire known range. Our elucidation of the CheX mechanism, together with our previous work on CheZ, set the stage for a unified hypothesis of response regulator phosphatases. Building on our success, we will identify factors that affect phosphodonor binding and autophosphorylation (Aim 1), autodephosphorylation (Aim 2), and sensor kinase-mediated dephosphorylation (Aim 3) of response regulators and characterize underlying mechanisms. Antibiotic resistance of bacterial and fungal pathogens is a major and increasing threat to human health. Our study of the binding of small molecules to response regulators may influence design of therapeutic agents to disable critical two-component systems of microbial pathogens. The results of our project could also be used to predict or manipulate the signaling kinetics of two-component systems, or engineer synthetic regulatory circuits with specific timing characteristics. Fundamental principles of signal transduction may also emerge. PUBLIC HEALTH RELEVANCE: Resistance of bacterial and fungal pathogens to killing by antibiotics is a major and increasing threat to human health. We will investigate fundamental properties of biological information processing systems, which are used by microorganisms to detect features of interest in their environment (such as the presence of a human, animal, or plant host) and respond appropriately (for example by commencing infection). Our work may influence design of therapeutic agents to disable regulatory systems that control virulence, viability, or drug susceptibility of microbial pathogens.

描述（由申请人提供）：对刺激的反应能力通常被认为是生活的关键特征。细胞可以检测新条件，将信息转换为可用的形式，并执行适当的响应。一种常见的信号转导策略是通过磷酸基在蛋白质上的特定和瞬态放置来表示信息。信号转导错误可能导致疾病（例如癌症，糖尿病），并且已经开发出来阻止异常信号过程。因此，了解蛋白质磷酸化的机制，调节和影响是基本的兴趣，并且对人类健康具有实际意义。 通过许多措施，微生物是地球上生命的主要形式，包括遗传多样性，原始数量，环境分布和进化经验。因此，寻求微生物中的基本信号转导原理是合乎逻辑的。我们的长期目标是对两个组件调节系统的信号转导的全面理解，这在所有三个系统发育领域的微生物中发生。在典型的两个组分系统中，传感器激酶检测刺激和自磷酸化。然后，响应调节剂从传感器激酶（或小分子）催化磷酸化，从而打开响应。反应调节剂去磷酸化，无论是由磷酸酶培养或介导的，都结束了反应。磷酸基反应的动力学对于将反应与刺激同步很重要。 基因组测序提出了一个挑战（已知蛋白质数量和可以研究的内容之间的差距迅速扩大）和机会（多样化且广泛的序列数据）。为了学习如何仅从序列数据中揭示数万个两组分蛋白的特性，我们的创新研究策略着重于传感器激酶或响应调节剂的保守域之间的序列差异（而不是相似性）。在上一个赠款期间，我们的生产力是一种综合生物化学，生物信息学，生物物理学，遗传学，分子生物学和结构生物学的方法。我们确定了极大地影响响应调节剂反应速率但没有考虑到整个已知范围的因素。我们阐明了CHEX机制，以及我们先前在Chez上的工作，为统一的响应调节剂磷酸酶的假设奠定了基础。在我们的成功的基础上，我们将确定影响磷酸化结合和自磷酸化的因素（AIM 1），自磷酸化（AIM 2）和传感器激酶介导的响应调节剂的去磷酸化（AIM 3）并表征了基本机制。 细菌和真菌病原体的抗生素耐药性是对人类健康的主要威胁。我们对小分子与响应调节剂结合的研究可能会影响治疗剂的设计，以禁用微生物病原体的关键两组分组系统。我们项目的结果也可用于预测或操纵两组分系统的信号动力学，或具有特定时间定时特征的工程师合成调节电路。信号转导的基本原理也可能出现。 公共卫生相关性：细菌和真菌病原体对用抗生素杀死的耐药性是对人类健康的主要威胁。我们将研究生物信息处理系统的基本特性，微生物用于检测其环境中感兴趣的特征（例如人类，动物或植物宿主的存在）并做出适当反应（例如，开始感染）。我们的工作可能会影响治疗剂的设计，以禁用控制毒力，活力或微生物病原体药物敏感性的调节系统。