CHEMOTACTIC SENORY TRANSDUCTION IN BACILLUS SUBTILIS

枯草芽孢杆菌中的趋化感觉转导

• 批准号: 6519753
• 负责人: George W. Ordal
• 金额: $ 32.74万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 1983
• 资助国家: 美国
• 起止时间: 1983-08-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6519753
• 关键词: Bacillus subtilis; asparagine; bacterial proteins; chemotaxis; high performance liquid chromatography; ligands; methylation; phosphorylation; phosphotransferases; polymerase chain reaction; protein protein interaction; protein structure function; receptor; receptor binding; sensory receptors

DESCRIPTION: (Adapted from the Investigator's Abstract) One major outcome of the study of chemotaxis during the past decade is that the well-studied enteric model may not be representative of archaea and eubacteria ("bacteria'). Taxis in the archeon Halobacterium salinarum bears some remarkable similarities to that in Bacillus subtilis, a finding that suggests that the ancestral mechanism might have been closer to these mechanisms, rather than to the simplified mechanism in the enteric bacteria. For this reason, this work might establish a new paradigm for chemotaxis, which may be followed by the great sweep of eubacteria and archaea. It is becoming increasingly clear that complexes of receptors with other proteins control output, not just in chemotaxis but in many systems. However, bacterial chemotaxis is an especially good model system as virtually any combination of mutations, including the charge at each site of receptor methylation, can be used to ask specific questions and the effects studied in vivo and in vitro. In this proposal we are focusing on the interactions among chemotaxis proteins, including the receptors and the excitatory CheA kinase, in order to define the structure/function relationships. Our recent experiments have led to the hypothesis that CheY-P feeds back on the receptor to inhibit CheA during adaptation and may even be hydrolyzed at the receptor, unknown features in Escherichia coli chemotaxis. Such an interaction may occur in H. salinarum and may represent the ancestral adaptation mechanism. It appears that the receptors control CheY-P levels through differential regulation of the state of methylation/amidation of each of the sites of receptor methylation. Some proteins have no counterparts in E. coli -- CheC, CheD, and CheV. It appears that CheC/CheD, present also in H. salinarum, controls the processes that regulate CheY-P levels. Phosphorylation of CheV helps bring about adaptation. Exploring these subjects may revolutionize our understanding of how chemotaxis works in B. subtilis and perhaps in many bacteria. The goal is to elucidate these specific hypotheses or findings. Where the receptors and CheY-P interact and the consequences of the interaction in vivo and in vitro will be determined. The effect of CheV on this interaction will be explored. How degree of methylation at each site in the asparagine receptor, McpB, affects CheA and the CheY-P interaction as well as behavior will be quantitated. The purpose and location of interactions of CheC and CheD with each other and with McpB and CheA (in the case of CheC) will be elucidated. The (fast) kinetics of CheA autophosphorylation and phosphotransfer to CheY, CheB, and CheV and their purposes will be studied. The effect of receptor interaction on these kinetics will be explored.

描述：（根据调查员的摘要进行了改编） 在过去的十年中，趋化性的研究是肠道良好的肠 模型可能无法代表古细菌和花生（“细菌”）。出租车 在大周围的盐酸盐中，萨利纳姆与 在枯草芽孢杆菌中，这一发现表明祖先机制 可能已经接近这些机制，而不是简化 肠细菌中的机制。因此，这项工作可能会建立 趋化性的新范式，随后可能是 Eubacteria和古细菌。越来越清楚的是 具有其他蛋白质控制输出的受体，不仅在趋化性中，而且在 许多系统。但是，细菌趋化性是一个特别好的模型系统 几乎是突变的任何组合，包括每个位置的电荷 受体甲基化，可用于提出特定问题和效果 在体内和体外研究。在这个建议中，我们专注于 趋化蛋白之间的相互作用，包括受体和 兴奋性CHEA激酶，以定义结构/功能 关系。我们最近的实验导致了Chey-P的假设 反馈受体以抑制适应过程中的CHEA，甚至可能是 在受体中水解，大肠杆菌趋化性的未知特征。 这种相互作用可能发生在盐氏菌中，可能代表祖先 适应机制。看来受体控制chey-p水平 通过对甲基化状态/胺化状态的差异调节 受体甲基化部位的位置。有些蛋白质在E中没有对应物。 大属 - Chec，Ched和Chev。看来Chec/Ched也存在于H. Salinarum控制调节Chey-P水平的过程。磷酸化 CHEV有助于适应。探索这些主题可能 彻底改变了我们对在枯草芽孢杆菌和 也许在许多细菌中。目的是阐明这些特定的假设或 发现。受体和chey-p相互作用的地方以及 将确定体内和体外的相互作用。 CHEV对此的影响 将探索互动。如何在每个地点的甲基化程度 天冬酰胺受体MCPB影响CHEA和CHEY-P相互作用以及 行为将被定量。 CHEC相互作用的目的和位置 彼此之间以及MCPB和Chea（在CHEC的情况下）将是 阐明。 CHEA自磷酸化和磷酸转移的（快速）动力学 将研究Chey，Cheb和Chev及其目的。效果 将探索这些动力学上的受体相互作用。