Skataric Maja, Nikolaev Evgeni V, Sontag Eduardo D
Department of Electrical and Computer Engineering, Rutgers University, Piscataway, NJ 08854-8019, USA.
Department of Mathematics, Rutgers University, Piscataway, NJ 08854-8019, USA.
IET Syst Biol. 2015 Feb;9(1):1-15. doi: 10.1049/iet-syb.2014.0006.
The phenomenon of fold-change detection, or scale-invariance, is exhibited by a variety of sensory systems, in both bacterial and eukaryotic signalling pathways. It has been often remarked in the systems biology literature that certain systems whose output variables respond at a faster time scale than internal components give rise to an approximate scale-invariant behaviour, allowing approximate fold-change detection in stimuli. This study establishes a fundamental limitation of such a mechanism, showing that there is a minimal fold-change detection error that cannot be overcome, no matter how large the separation of time scales is. To illustrate this theoretically predicted limitation, the authors discuss two common biomolecular network motifs, an incoherent feedforward loop and a feedback system, as well as a published model of the chemotaxis signalling pathway of Dictyostelium discoideum.
倍数变化检测现象，即尺度不变性，在细菌和真核生物信号通路的多种感觉系统中都有表现。系统生物学文献中经常提到，某些系统的输出变量比内部组件响应更快的时间尺度，会产生近似的尺度不变行为，从而允许对刺激进行近似的倍数变化检测。本研究确定了这种机制的一个基本限制，表明存在一个最小的倍数变化检测误差，无论时间尺度的分离有多大，都无法克服。为了从理论上说明这一预测的限制，作者讨论了两种常见的生物分子网络基序，即非相干前馈环和反馈系统，以及已发表的盘基网柄菌趋化信号通路模型。
