Structure and function of membrane receptor signaling complex in bacterial chemot

细菌趋化细胞膜受体信号复合物的结构和功能

基本信息

批准号：
8520324
负责人：
Peijun Zhang
金额：
$ 26.43万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-17 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8520324
关键词：
Affect Architecture Area Binding Biochemical Biological Assay Biological Models Biology Cell Differentiation process Cells Chemicals Chemoreceptors Chemotaxis Circadian Rhythms Complex Computer Simulation Coupling Cryoelectron Microscopy Development Docking Environment Enzymes Escherichia coli Eukaryotic Cell Flagella Foundations Health Histidine In Vitro Individual Infection Ligand Binding Ligands Maps Mediating Medicine Membrane Membrane Structure and Function Methods Modeling Modification Molecular Molecular Conformation Molecular Models Monitor Motor Mutagenesis Nature Pathogenesis Phosphotransferases Plants Play Process Prokaryotic Cells Proteins Receptor Activation Receptor Signaling Resolution Response to stimulus physiology Role Rotation Sensory Signal Pathway Signal Transduction Signal Transduction Pathway Signaling Molecule Site-Directed Mutagenesis Stimulus Structural Models Structure System Testing antimicrobial drug cell motility chemical binding computerized data processing crosslink drug development electron crystallography electron tomography in vivo insight interest microorganism molecular modeling novel pathogen protein-histidine kinase receptor reconstitution response scaffold three dimensional structure

项目摘要

DESCRIPTION (provided by applicant): Bacterial cells respond to the changes in their chemical environment (chemotaxis) by binding of the chemical ligand to membrane receptors, activating the multi-protein receptor signaling complex, and generating a diffusible intracellular signal that ultimately regulates the rotation of the flagella motor. The chemotactic signaling pathway in E. coli has emerged as the best-characterized signal transduction network in biology. All the protein components responsible for excitation and adaptation have been identified and characterized, and their soluble domain structures determined to atomic resolution. There have also been numerous mutagenesis, chemical cross-linking and GFP-tagging studies on chemotaxis signaling. However, the structures of the basic signaling unit consisting of the receptor, the kinase CheA and coupling protein CheW, that are essential to understand the molecular mechanism of the signal transduction remain elusive. The studies described in this proposal are targeted to obtaining high resolution structures of the ternary receptor signaling complex, as well as structures of its higher order assembly in intact cells, primarily by high resolution three-dimensional cryo- electron microscopy. We will also characterize the conformational changes of the complex upon receptor activation/inactivation using both structural methods and functional assays. These structures, combining with functional and biochemical analysis, are expected to provide a detailed understanding on how minute external chemical signals are transmitted to the histidine kinase and amplified through a large assembly of signaling complexes within the native cells. These results will also provide a foundation for generating computational models of receptor signaling systems, since the E. coli chemotaxis has been an ideal model system for understanding the molecular mechanisms of signal transduction and signal processing in general. PUBLIC HEALTH RELEVANCE: The mechanism of stimulus-response coupling in bacterial chemotaxis has emerged as a paradigm for understanding the principles of intracellular signal transduction both in bacterial and eukaryotic cells. E. coli chemotaxis is also a representative of the highly conserved "two-component systems" that control processes ranging from cell differentiation and development to circadian rhythms and pathogenesis in prokaryotes including both eubacterial and archaeal species. These systems all contain two central enzymes, a histidine protein kinase and a response regulator that mediates phosphor relay signal transduction networks in microorganisms and plants. In addition, bacterial chemotaxis response is crucial for colonization and infection, and the signal transduction systems that mediate such responses are potential targets for antimicrobial drug development. A deeper understanding of the mechanism of signaling in bacterial chemotaxis is therefore of great interests for many areas of biology and medicine. Our proposed efforts for a comprehensive and integrated structural and functional analysis of chemotaxis receptor signaling complexes and complex arrays will provide insight into receptor-kinase interaction, signaling complex formation, sensory cluster formation and conformation coupling, and contribute to a better understanding of the signal transduction and signal processing in general.

描述（由申请人提供）：细菌细胞通过结合化学配体与膜受体的结合来应对其化学环境（趋化性）的变化，激活多蛋白受体信号传导复合物，并产生可扩散的细胞内信号，最终调节鞭毛运动的旋转。大肠杆菌中的趋化信号通路已成为生物学中最佳特征的信号转导网络。所有负责激发和适应性的蛋白质成分均已鉴定和表征，并且其可溶性域结构确定为原子分辨率。关于趋化性信号传导的诱变，化学交联和GFP标记研究也有许多。但是，由受体，激酶CHEA和偶联蛋白咀嚼组成的基本信号单元的结构对于了解信号转导的分子机制至关重要。该提案中描述的研究旨在获得三元受体信号传导复合物的高分辨率结构，以及其完整细胞中其高阶组装的结构，主要是通过高分辨率的三维冷冻元素显微镜。我们还将使用结构方法和功能分析来表征该复合物在受体激活/灭活后复合物的构象变化。这些结构与功能和生化分析结合在一起，预计将对如何传输到组氨酸激酶的微小外部化学信号并通过天然细胞内的大量信号复合物进行扩增提供详细的理解。这些结果还将为生成受体信号系统的计算模型提供基础，因为大肠杆菌趋化性是理想的模型系统，用于理解一般的信号转导和信号处理的分子机制。公共卫生相关性：细菌趋化性中刺激反应耦合的机制已成为理解细菌和真核细胞中细胞内信号转导原理的范式。大肠杆菌趋化性也是高度保守的“两个组分系统”的代表，该系统控制从细胞分化和发育到昼夜节律的循环以及包括Eubacterial和古细菌种类的原核生物中的发病机理。这些系统都包含两种中心酶，一个组氨酸蛋白激酶和一个介导微生物和植物中磷光继电器信号转导网络的反应调节剂。此外，细菌趋化反应对于定植和感染至关重要，介导此类反应的信号转导系统是抗菌药物发育的潜在靶标。因此，对细菌趋化性中信号的机制有更深入的了解对于许多生物学和医学领域都具有极大的利益。我们提出的对趋化受体信号传导复合物和复杂阵列进行全面和整合的结构和功能分析的努力将为受体激酶相互作用，信号传导复合物的形成，感觉群集形成和构象耦合提供深入了解，并有助于更好地理解信号转移和一般信号处理。

项目成果

期刊论文数量（8）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

An intramolecular salt bridge drives the soluble domain of GTP-bound atlastin into the postfusion conformation.

DOI：
10.1083/jcb.201105006
发表时间：
2011-11-14
期刊：
The Journal of cell biology
影响因子：
0
作者：
Morin-Leisk J;Saini SG;Meng X;Makhov AM;Zhang P;Lee TH
通讯作者：
Lee TH

Low-dimensional nanoparticle clustering in polymer micelles and their transverse relaxivity rates.

DOI：
10.1021/nn400824b
发表时间：
2013-07-23
期刊：
ACS nano
影响因子：
17.1
作者：
Hickey RJ;Meng X;Zhang P;Park SJ
通讯作者：
Park SJ

Peptide-Directed Assembly of Single-Helical Gold Nanoparticle Superstructures Exhibiting Intense Chiroptical Activity.

DOI：
10.1021/jacs.6b07322
发表时间：
2016-10-19
期刊：
Journal of the American Chemical Society
影响因子：
15
作者：
Merg AD;Boatz JC;Mandal A;Zhao G;Mokashi-Punekar S;Liu C;Wang X;Zhang P;van der Wel PCA;Rosi NL
通讯作者：
Rosi NL

Size-controlled self-assembly of superparamagnetic polymersomes.