Moreno-Gámez Stefany, Sorg Robin A, Domenech Arnau, Kjos Morten, Weissing Franz J, van Doorn G Sander, Veening Jan-Willem
Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands.
Groningen Institute for Evolutionary Life Sciences, University of Groningen, P.O. Box 11103, 9700 CC, Groningen, The Netherlands.
Nat Commun. 2017 Oct 11;8(1):854. doi: 10.1038/s41467-017-00903-y.
Streptococcus pneumoniae becomes competent for genetic transformation when exposed to an autoinducer peptide known as competence-stimulating peptide (CSP). This peptide was originally described as a quorum-sensing signal, enabling individual cells to regulate competence in response to population density. However, recent studies suggest that CSP may instead serve as a probe for sensing environmental cues, such as antibiotic stress or environmental diffusion. Here, we show that competence induction can be simultaneously influenced by cell density, external pH, antibiotic-induced stress, and cell history. Our experimental data is explained by a mathematical model where the environment and cell history modify the rate at which cells produce or sense CSP. Taken together, model and experiments indicate that autoinducer concentration can function as an indicator of cell density across environmental conditions, while also incorporating information on environmental factors or cell history, allowing cells to integrate cues such as antibiotic stress into their quorum-sensing response. This unifying perspective may apply to other debated quorum-sensing systems.Peptide CSP regulates natural competence in pneumococci and has been proposed as a quorum-sensing signal or a probe for sensing environmental cues. Here, the authors show that CSP levels can indeed act as an indicator of cell density and also incorporate information on environmental factors or cell history.
肺炎链球菌在暴露于一种名为感受态刺激肽（CSP）的自诱导肽时会变得具有遗传转化能力。这种肽最初被描述为一种群体感应信号，使单个细胞能够根据群体密度调节感受态。然而，最近的研究表明，CSP可能反而充当一种探测环境线索的探针，比如抗生素压力或环境扩散。在这里，我们表明感受态诱导可同时受到细胞密度、外部pH值、抗生素诱导的压力和细胞历史的影响。我们的实验数据由一个数学模型来解释，在该模型中，环境和细胞历史会改变细胞产生或感知CSP的速率。综合来看，模型和实验表明，自诱导剂浓度可以作为跨环境条件下细胞密度的指标，同时还纳入了有关环境因素或细胞历史的信息，使细胞能够将诸如抗生素压力等线索整合到其群体感应反应中。这种统一的观点可能适用于其他存在争议的群体感应系统。肽CSP调节肺炎球菌的自然感受态，并已被提议作为一种群体感应信号或探测环境线索的探针。在这里，作者表明CSP水平确实可以作为细胞密度的指标，并且还纳入了有关环境因素或细胞历史的信息。
