BEHAVIOR OF BACTERIA--BIOCHEMISTRY AND GENETICS

细菌的行为——生物化学和遗传学

• 批准号: 2191156
• 负责人: JULIUS ADLER
• 金额: $ 14.62万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-18 至 1999-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2191156
• 关键词: Escherichia coli; bacteria; bacterial genetics; cell migration; cell osmotic pressure; chemoreceptors; chemotaxis; electrophysiology; flagellum; mechanoreceptors; membrane channels; microorganism metabolism; mutant; orientation; photobiology; photostimulus; stimulus /response; temperature; voltage /patch clamp

Motile bacteria such as Escherichia coil are attracted by certain chemicals and repelled by others, a process known as chemotaxis. In addition, these bacteria are attracted by certain physical stimuli and repelled by others: for example, 1) light brings about phototaxis; 2) temperature, thermotaxis; and 3) osmolarity, osmotaxis. Work proposed in this application aims to understand how these physical stimuli function to bring about these behavioral responses. In the case of chemicals, the stimuli are sensed by some twenty different chemoreceptors. These send their information to four different transducers called Methyl-accepting Chemotaxis Proteins the MCPs; in some cases the chemoreceptors actually are the MCPs. In a process known as excitation, MCP by way of phosphorylated or dephosphorylated chemotaxis (Che) proteins tells the flagella whether to rotate counterclockwise and thus bring about running in the case of attractants, or whether to rotate clockwise and thus bring about tumbling in the case of repellents. Then excitation is shut off (even though the attractant or repellent is still present) by a process known as adaptation: This consists of a change in the level of methylation of MCP. In the case of physical stimuli, work reported here and experiments proposed here aim to find out if this same mechanism also applies. It appears that in certain cases it might while in other cases this mechanism is bypassed. Physical stimuli have been and will be identified, and how the responses occur have partially been or will be elucidated. The mechanisms discovered here will hopefully have relevance to understanding neurobiology and behavior in higher organisms, including man. Further, diseases of the nervous system can perhaps be understood by results of the kinds found here.

可移动的细菌，如大肠杆菌，会被某些 化学物质和被其他物质排斥，这一过程称为趋化性。在……里面 此外，这些细菌会被某些物理刺激所吸引 被其他人排斥：例如，1)光导致趋光性；2) 温度，亲热性；3)渗透性，亲渗性。建议开展的工作 此应用程序旨在了解这些物理刺激是如何发挥作用的 带来这些行为反应。 就化学物质而言，刺激物是由大约二十种不同的 化学感受器。这些传感器将它们的信息发送到四个不同的传感器 被称为甲基接受趋化蛋白；在某些情况下 化学感受器实际上是MCP。在一个被称为激励的过程中， 通过磷酸化或去磷酸化的趋化蛋白(CHE)实现的MCP 告诉鞭毛是否逆时针旋转，从而使 在吸引剂的情况下运行，或者是否顺时针旋转和 从而在驱避剂的情况下导致翻滚。那么激励就是 关闭(即使引诱剂或驱避剂仍然存在) 被称为适应的过程：这包括以下水平的变化 MCP的甲基化。在物理刺激的情况下，这里报告的工作 这里提出的实验旨在找出同样的机制是否也 适用。它似乎在某些情况下是可能的，而在其他情况下 这个机制被绕过了。身体刺激曾经是，也将是 已经确定，以及响应如何发生已经或将部分地 已澄清。 这里发现的机制有望与 了解高等生物的神经生物学和行为，包括 天哪。此外，神经系统疾病或许可以通过 在这里发现的各种结果。