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: 7931609
• 负责人: Robert B. Bourret
• 金额: $ 7.1万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7931609
• 关键词: Accounting; Active Sites; Affect; Amino Acid Sequence; Amino Acid Substitution; Amino Acids; Antibiotic Resistance; Archaea; Bacteria; Bacterial Drug Resistance; Behavior; Binding; Biochemistry; Bioinformatics; Biological; Biological Assay; Biological Process; Biophysics; Cells; Characteristics; Development; Elements; Engineering; Environment; Eukaryota; Excision; Frequencies; Genetic; Genetic Variation; Goals; Growth; Health; Human; Ionic Strengths; Kinetics; Knowledge; Length; Life; Malignant Neoplasms; Measures; Methods; Microbe; Modeling; Molecular; Molecular Biology; OmpR protein; Output; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiology; Plants; Positioning Attribute; Prokaryotic Cells; Property; Protein Dephosphorylation; Protein Family; Protein Kinase; Proteins; Reaction; Regulation; Role; Signal Transduction; Speed; Stimulus; Structure; Substrate Specificity; System; Temperature; Testing; Therapeutic Agents; Time; Translating; Virulence; Water; Work; acetyl phosphate; cell growth; design; gain of function; gain of function mutation; inhibitor/antagonist; innovation; insight; interest; microorganism; mutant; pathogen; reaction rate; response; sensor; small molecule; structural biology

DESCRIPTION (provided by applicant: All living cells use signal transduction to detect properties of interest in their environment, create an internal representation of stimuli, and generate an appropriate response to changing conditions. Errors in signal transduction can have serious consequences, such as cell growth without a growth stimulus (i.e. cancer). In both prokaryotes and eukaryotes, information is often encoded as the presence or absence of a phosphoryl group specifically attached to a protein. Understanding the mechanisms and regulation of phosphoryl group transfer among proteins, and the impact of phosphorylation on protein activity, is therefore of broad interest. Because microorganisms constitute the vast majority of life on Earth in terms of both numbers and genetic diversity, microbes are logical subjects in which to seek fundamental biological principles generally applicable to all forms of life. Two-component regulatory systems are widely used for signal transduction by bacteria, archaea, eukaryotic microorganisms, and plants (but not humans). A sensor kinase protein detects stimuli and converts them to phosphoryl groups, which are transferred to a response regulator protein to control responses such as behavior, development, physiology, or virulence. Our long-term goal is to achieve a comprehensive understanding of two-component signal transduction. In this proposal, we will investigate the mechanisms and kinetics by which response regulators switch between phosphorylated (active) and unphosphorylated (inactive) states. In order to synchronize responses with stimuli, the kinetics of signaling biochemistry must match the timescale of the affiliated biological process. Response regulators can self-catalyze phosphoryl group addition and removal. Auxiliary kinases and phosphatases substantially accelerate response regulator autocatalytic reactions to achieve physiologically appropriate signaling speeds, but do not alter the intrinsic reaction mechanisms. Although all response regulators share a conserved structure and catalytic residues, autodephosphorylation rates vary by >40,000x. Aims 1 and 2 focus on identifying factors that control rates of response regulator self dephosphorylation and phosphorylation, and understanding how these elements exert their influence. Our experimental strategy integrates biochemistry, bioinformatics, genetics, and structural biology to alter nonconserved residues in the active sites of various response regulators and determine the functional and structural consequences of doing so. Aims 3 and 4 investigate several specific auxiliary phosphatases (e.g. CheZ, CheX, PhoR) in detail to determine what common mechanistic, regulatory, or structural features may exist among this poorly characterized group of proteins. Antibiotic resistance is a major and increasing threat to human health. This work may impact design of therapeutic agents to attack two-component systems that control virulence or viability of bacterial and fungal pathogens. In addition, the knowledge gained could be used to predict or manipulate the signaling kinetics of two-component systems, or engineer synthetic regulatory circuits with specific timing characteristics.

描述（由申请人提供：所有活细胞都使用信号转导来检测其环境中感兴趣的特性，创建刺激的内部表示，并对变化的条件产生适当的响应。信号转导的错误可能会带来严重的后果，例如没有生长刺激的细胞生长（即癌症）。因此，了解蛋白质之间的机制和调节，以及磷酸化对蛋白质活性的影响是广泛的，因为微生物构成了地球上绝大多数生命的数量，而遗传多样性则是逻辑上的逻辑受试者，以寻求基本生物学原理。古细菌，真核微生物和植物（但不是人类）。传感器激酶蛋白会检测到刺激，并将其转换为响应调节蛋白，以控制行为，生理学或抗态度的综合性，响应调节因素在磷酸化（活跃）和未磷酸化（不活跃的）状态下切换，以使响应与刺激同步，信号传导生物化学的动力学必须与关联的生物学过程相匹配。在生理上适当的信号传导速度，但没有改变固有的反应机制，尽管所有响应调节剂具有保守的结构和催化残基，但自动磷酸化速率均在识别响应速率自我DEPHOSPHORTION和PHOPHOSPRATION的效果上的效果上，均为40,000 X生物信息学，遗传学和结构生物学改变了各种反应调节剂的活跃部位，并确定这样做的功能和结构后果，目的是3和4。对人类健康的威胁增加可能会影响治疗剂的设计，以攻击两个组件的系统，以控制细菌和真菌病原体的毒力或生存能力。