Ratiometric population sensing by a pump-probe signaling system in Bacillus subtilis
Ratiometric population sensing by a pump-probe signaling system in Bacillus subtilis
复制标题
抽运-探测信号系统在枯草芽孢杆菌中的比率种群传感
DOI：
10.1038/s41467-020-14840-w
复制
发表时间：
2020-03-04
影响因子：
16.6
通讯作者：
Bischofs, Ilka B.
中科院分区：
文献类型：
--
作者：
Babel, Heiko;Naranjo-Meneses, Pablo;Bischofs, Ilka B.
通过可扩散的信号分子进行通信有助于更高水平的细胞群体组织。革兰氏阳性细菌经常使用信号肽，这些信号肽要么在细胞表面被检测到，要么被泵入细胞质后被细胞内的受体“探测”。虽然前者用于监测细胞密度，但泵浦-探测网络的功能不太清楚。在这里，我们展示了泵浦-探测网络原则上可以执行不同的任务，并调节群体感应、计时和比率控制。我们使用FRET表征了枯草芽孢杆菌中原型Phra-RapA系统的性质。我们发现，细胞外Phra浓度的变化被跟踪得相当差；相反，细胞以一种剂量依赖的方式积累并强烈放大信号。这表明Phra-Rapa系统和其他类似的系统已经进化到能够感知不同种群组成的变化，并推断混合种群中产生信号的细胞的比例，以协调细胞行为。
Communication by means of diffusible signaling molecules facilitates higher-level organization of cellular populations. Gram-positive bacteria frequently use signaling peptides, which are either detected at the cell surface or 'probed' by intracellular receptors after being pumped into the cytoplasm. While the former type is used to monitor cell density, the functions of pump-probe networks are less clear. Here we show that pump-probe networks can, in principle, perform different tasks and mediate quorum-sensing, chronometric and ratiometric control. We characterize the properties of the prototypical PhrA-RapA system in Bacillus subtilis using FRET. We find that changes in extracellular PhrA concentrations are tracked rather poorly; instead, cells accumulate and strongly amplify the signal in a dosedependent manner. This suggests that the PhrA-RapA system, and others like it, have evolved to sense changes in the composition of heterogeneous populations and infer the fraction of signal-producing cells in a mixed population to coordinate cellular behaviors.