Active transport improves the precision of linear long distance molecular signalling
Active transport improves the precision of linear long distance molecular signalling
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DOI：
10.1088/1751-8113/49/36/364001
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发表时间：
2016-09-09
影响因子：
2.1
通讯作者：
Metzler, Ralf
中科院分区：
文献类型：
--
作者：
Godec, Aljaz;Metzler, Ralf
活细胞中的分子信号发生在低拷贝数，从而固有地受到热扩散施加的噪声的限制。生物化学受体计数信号分子的精度与噪声相关时间密切相关。除了被动热扩散，信使RNA和囊泡吞噬的信号分子可以瞬时结合到分子马达上，并在生物细胞中主动运输。主动运输在远距离运输时最为有利，例如在神经元中可达1米的量级。在这里，我们解释如何间歇性主动运输允许更快的平衡后，由生化刺激引发的浓度变化。此外，我们展示了如何间歇性的主动漂移引起的噪声在有效的一维系统，如树突的质的变化。因此，它们允许在由受体读出的浓度的较小相对偏差的意义上显著改善的信号传导精度。根据线性响应理论，我们导出了计算主动输运分子的精确平均场精度极限。我们解释了间歇性的活动偏移如何破坏分子运动中的复发，从而有助于提高信号传导的准确性。我们的研究结果提供了更深入的了解复发如何影响生物细胞和新型医疗诊断设备中的分子信号精度。
Molecular signalling in living cells occurs at low copy numbers and is thereby inherently limited by the noise imposed by thermal diffusion. The precision at which biochemical receptors can count signalling molecules is intimately related to the noise correlation time. In addition to passive thermal diffusion, messenger RNA and vesicle-engulfed signalling molecules can transiently bind to molecular motors and are actively transported across biological cells. Active transport is most beneficial when trafficking occurs over large distances, for instance up to the order of 1 metre in neurons. Here we explain how intermittent active transport allows for faster equilibration upon a change in concentration triggered by biochemical stimuli. Moreover, we show how intermittent active excursions induce qualitative changes in the noise in effectively one-dimensional systems such as dendrites. Thereby they allow for significantly improved signalling precision in the sense of a smaller relative deviation in the concentration read-out by the receptor. On the basis of linear response theory we derive the exact mean field precision limit for counting actively transported molecules. We explain how intermittent active excursions disrupt the recurrence in the molecular motion, thereby facilitating improved signalling accuracy. Our results provide a deeper understanding of how recurrence affects molecular signalling precision in biological cells and novel medical-diagnostic devices.