Signal transduction and adaptation by polymodal receptors

多模式受体的信号转导和适应

• 批准号: 11480190
• 负责人: KAWAGISHI Ikuro
• 金额: $ 9.54万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11480190/
• 关键词: Escherichia coli; chemotaxis; signal transduction; pH; temperature; adaptation; protein methylation; protein-protein interaction; 細菌; 走性; 分子認識; Escherichia coli; chemotaxis; signal transduction; pH; temperature; adaptation; protein methylation; protein-protein interaction; 細菌; 走性; 分子認識

The chemotaxis in Escherichia coli and Salmonella typhimurium has been serving as a model system to study signal transduction pathways at the molecular level. The transmembrane chemoreceptors sense environmental stimuli, including chemoattractants , chemorepellents, pH and temperature, and transmit signals to the cytoplasmic histidine kinase CheA. Persisting stimulation causes adaptation via methylation/demethylation of the relevant chemoreceptor. In this study, we have focused on polymodal sensing of the chemoreceptors and the mechanisms of adaptation through interaction between a receptor and the methyltransferase CheR. We obtained various important results concerning the following topics that provide new insights into the mechanisms underlying the chemotactic signal transduction : (i) the recognition of citrate by the chemoreceptor Tcp (published) ; (ii) the involvement of the "linker" region in the recognition of pH by the chemoreceptors, Tar and Tsr (published) ; (iii) the involvement of the transmembrane regions in thermosensing by the chemoreceptors, Tar and Tap (in preparation) ; (iv) role of the C-terminal pentapeptide sequence of the chemoreceptors in the binding of CheR (published ; submitted) ; (v) dual recognition of the bacterial chemoreceptor Tar by chemotaxis-specific domains of the CheR methyltransferase (submitted) ; (vi) the effect of methylation of the chemoreceptor Tar on its ligand-binding affinity (in preparation) ; and (vii) the roles of the three cheA homologs in chemotaxis of Vibrio cholerae (published).

大肠杆菌和鼠伤寒沙门氏菌的趋化性一直是研究分子水平上信号转导途径的模型系统。跨膜化学感受器感知环境刺激，包括化学吸引剂，化学植物，pH和温度，并将信号传输到细胞质组氨酸激酶CHEA。持续的刺激通过相关化学感受器的甲基化/去甲基化引起适应。在这项研究中，我们专注于化学感受器的多峰传感以及通过受体与甲基转移酶ChER之间的相互作用而适应的机制。我们获得了有关以下主题的各种重要结果，这些主题为趋化信号转导的机制提供了新的见解：（i）化学感受器TCP对柠檬酸盐的识别（已发布）； （ii）化学感受器TAR和TSR（已发表）的“接头”区域参与pH值； （iii）化学感受器，焦油和水龙头（制备中）跨膜区域参与热效； （iv）化学感受器的C末端五肽序列在CHER结合中的作用（已发布；提交）； （v）通过Cher甲基转移酶的趋化性特异性结构域对细菌化学感受器TAR的双重识别（已提交）； （vi）化学感受器焦油对配体结合亲和力的甲基化（准备）； （vii）三个CHEA同源物在弧菌霍乱的趋化性中的作用（已发表）。