期刊
MOLECULAR SYSTEMS BIOLOGY
卷 6, 期 -, 页码 -出版社
WILEY
DOI: 10.1038/msb.2010.37
关键词
adaptation; feedback; fluorescence resonance energy transfer (FRET); frequency response; Monod-Wyman-Changeux (MWC) model
资金
- National Institutes of Health [AI016478, GM081747, AI063747]
- NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES [R01AI016478, F32AI063747, R37AI016478] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [R01GM081747] Funding Source: NIH RePORTER
The Escherichia coli chemotaxis-signaling pathway computes time derivatives of chemoeffector concentrations. This network features modules for signal reception/amplification and robust adaptation, with sensing of chemoeffector gradients determined by the way in which these modules are coupled in vivo. We characterized these modules and their coupling by using fluorescence resonance energy transfer to measure intracellular responses to time-varying stimuli. Receptor sensitivity was characterized by step stimuli, the gradient sensitivity by exponential ramp stimuli, and the frequency response by exponential sine-wave stimuli. Analysis of these data revealed the structure of the feedback transfer function linking the amplification and adaptation modules. Feedback near steady state was found to be weak, consistent with strong fluctuations and slow recovery from small perturbations. Gradient sensitivity and frequency response both depended strongly on temperature. We found that time derivatives can be computed by the chemotaxis system for input frequencies below 0.006 Hz at 22 degrees C and below 0.018 Hz at 32 degrees C. Our results show how dynamic input-output measurements, time honored in physiology, can serve as powerful tools in deciphering cell-signaling mechanisms. Molecular Systems Biology 6: 382; published online 22 June 2010; doi:10.1038/msb.2010.37
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据