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

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作为在分子水平上研究信号转导途径的模型系统。跨膜化学感受器感知环境刺激，包括化学引诱剂、化学排斥剂、pH 和温度，并将信号传递给细胞质组氨酸激酶 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，我们重点关注化学感受器的多模式传感以及通过受体与甲基转移酶 CheR 之间相互作用的适应机制。我们获得了有关以下主题的各种重要结果，这些结果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（已发表）； (ii)“连接子”区域参与化学感受器 Tar 和 Tsr 识别 pH 值（已发表）； (iii) 跨膜区域参与化学感受器 Tar 和 Tap 的热传感（准备中）； (iv) 化学感受器的 C 端五肽序列在 CheR 结合中的作用（已发表；已提交）； (v) CheR甲基转移酶的趋化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Tar的甲基化对其配体结合亲和力的影响(准备中)； (vii) 三种 cheA 同源物在霍乱弧菌趋化性中的作用（已发表）。

项目成果

Shiomi,D., Okumura,H., Homma,M., and Kawagishi,I.: "The aspartate chemoreceptor Tar is effectively methylated by binding to the methyltransferase mainly through hydrophobic interaction"Mol. Microbiol.. (in press). (2000)

Shiomi,D.、Okumura,H.、Homma,M. 和 Kawagishi,I.：“天冬氨酸化学感受器焦油主要通过疏水相互作用与甲基转移酶结合，从而被有效甲基化”Mol。

Gosink, K.K. et al.: "Analyses of the roles of the three cheA homologs in chemotaxis of Vibrio cholerae"J. Bacteriol.. 184. 1767-1771 (2002)

戈辛克，K.K.

Shiomi, D. et al.: "The aspartate chemoreceptor Tar is effectively methylated by binding to the methyltransferase mainly through hydrophobic interaction"Mol. Microbiol.. 36. 132-140 (2000)

Shiomi, D. 等人：“天冬氨酸化学感受器 Tar 主要通过疏水相互作用与甲基转移酶结合，从而被有效地甲基化”Mol。

Shiomi, D. et al.: "The aspartate chemoreceptor Tar is effectively methylated by binding to the methyltransferase mainly through hydrophobic interaction"Mol. Microbiol. 36. 132-140 (2000)

Shiomi, D. 等人：“天冬氨酸化学感受器 Tar 主要通过疏水相互作用与甲基转移酶结合，从而被有效地甲基化”Mol。

Umemura, T. et al.: "Sensing of cytoplasmic pH by bacterial chemoreceptors involves the linker region that connects the membrane-spanning and the signal-modulating helices"J. Biol. Chem.. 277. 1593-1598 (2000)

Umemura, T. 等人：“细菌化学感受器对细胞质 p​​H 值的感知涉及连接跨膜和信号调节螺旋的连接区域”J.