Noise reduction by diffusional dissipation in a minimal quorum sensing motif.
Noise reduction by diffusional dissipation in a minimal quorum sensing motif.
复制标题
DOI：
10.1371/journal.pcbi.1000167
复制
发表时间：
2008-08-29
影响因子：
4.3
通讯作者：
You L
中科院分区：
文献类型：
--
作者：
Tanouchi Y;Tu D;Kim J;You L
细胞相互作用受到相互作用分子数量的随机波动（噪声）的影响。噪声对自然和工程蜂窝网络的鲁棒功能提出了重大挑战。过去的研究分析了如何在细胞内水平上调节噪音。然而，细胞-细胞通讯可以提供一种互补策略，通过使细胞与其环境和其他细胞偶联来实现稳健的基因表达。为了深入了解这个问题，我们研究了群体感应（QS）的噪音调节，这是许多细菌通过产生和感应小的可扩散信号进行交流的机制。使用随机模型，我们分析了一个最小的QS基序在革兰氏阴性菌。我们的分析表明，扩散的QS信号，连同其转录调节因子的快速周转，衰减低频成分的外在噪音。我们把这种独特的机制称为“扩散耗散”，以强调扩散引起的快速信号转换（或耗散）的重要性。我们进一步表明，这种噪声衰减是一个更通用的监管基序，其中QS是一个实现的属性。我们的研究结果表明，在QS系统中，一个不稳定的转录调节因子可能有利于调节产生公共产品的昂贵蛋白质的表达。群体感应（QS）是许多细菌通过合成和检测微小的、可扩散的信号来调节基因表达的机制。自发现以来，QS已被证明可以控制许多类型细菌的多种生理功能。它为细菌提供了一种优雅的策略来感知它们的密度并实现协调的群体行为。通过随机建模，我们表明QS可以有效地减少其靶基因表达的变异性（“噪声”）。令人惊讶的是，噪声降低并不显著依赖于细菌的数量，而是由细菌与其环境通过信号扩散的耦合引起的。扩散使得信号快速周转，其与信号的同源受体的快速细胞内周转一起导致噪声降低。我们的工作表明，QS在实现强大的基因调控中发挥着独特的作用，这与在细胞内水平发挥作用的噪声调控机制不同。因此，它为QS的进化及其在合成基因电路构建中的应用提供了新的见解。
Cellular interactions are subject to random fluctuations (noise) in quantities of interacting molecules. Noise presents a major challenge for the robust function of natural and engineered cellular networks. Past studies have analyzed how noise is regulated at the intracellular level. Cell–cell communication, however, may provide a complementary strategy to achieve robust gene expression by enabling the coupling of a cell with its environment and other cells. To gain insight into this issue, we have examined noise regulation by quorum sensing (QS), a mechanism by which many bacteria communicate through production and sensing of small diffusible signals. Using a stochastic model, we analyze a minimal QS motif in Gram-negative bacteria. Our analysis shows that diffusion of the QS signal, together with fast turnover of its transcriptional regulator, attenuates low-frequency components of extrinsic noise. We term this unique mechanism “diffusional dissipation” to emphasize the importance of fast signal turnover (or dissipation) by diffusion. We further show that this noise attenuation is a property of a more generic regulatory motif, of which QS is an implementation. Our results suggest that, in a QS system, an unstable transcriptional regulator may be favored for regulating expression of costly proteins that generate public goods. Quorum sensing (QS) is a mechanism by which many bacteria regulate gene expression via the synthesis and detection of small, diffusible signals. Since its discovery, QS has been shown to control diverse physiological functions in numerous types of bacteria. It provides an elegant strategy for bacteria to sense their density and to achieve coordinated population behavior. By stochastic modeling, we show that QS can effectively reduce variability (“noise”) in the expression of its target genes. Surprisingly, the noise reduction does not significantly depend on the number of bacteria but rather results from the coupling of a bacterium and its environment through signal diffusion. Diffusion enables fast signal turnover, which, together with fast intracellular turnover of the cognate receptor of the signal, leads to noise reduction. Our work suggests a unique role of QS in achieving robust gene regulation, which is distinct from noise-regulation mechanisms that act at the intracellular level. As such, it offers novel insights into evolution of QS as well as its application in construction of synthetic gene circuits.
登录
查看更多内容
影响因子：
64.8
作者：
Becskei, A;Serrano, L
通讯作者：
Serrano, L
影响因子：
64.8
作者：
Austin, DW;Allen, MS;Simpson, ML
通讯作者：
Simpson, ML
DOI：
10.1073/pnas.0408507102
发表时间：
2005-03-08
影响因子：
11.1
作者：
Hooshangi, S;Thiberge, S;Weiss, R
通讯作者：
Weiss, R
影响因子：
64.8
作者：
DOUGLASS, JK;WILKENS, L;MOSS, F
通讯作者：
MOSS, F
影响因子：
3.2
作者：
GAMBELLO, MJ;IGLEWSKI, BH
通讯作者：
IGLEWSKI, BH