Coordination of the Arc Regulatory System and Pheromone-Mediated Positive Feedback in Controlling the Vibrio fischeri lux Operon
Coordination of the Arc Regulatory System and Pheromone-Mediated Positive Feedback in Controlling the Vibrio fischeri lux Operon
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电弧调节系统与信息素介导的正反馈在控制费氏弧菌操纵子中的协调
作者：
A. Septer;E. Stabb
细菌信息素信号传导通常由环境响应调节器和正反馈两者控制。这种调节组合有可能协调不同亚群之间的群体反应，不同的感知关键环境刺激。我们已经探索了环境响应调节器和信息素介导的正反馈之间的相互作用，在细胞间信号由弧菌fischeri ES 114，一种生物发光的细菌，定殖的鱿鱼Euprymna spectopes。ES 114中的生物发光部分由N-（3-氧代己酰基）-L-高丝氨酸内酯（3 OC 6）控制，该内酯是由LuxI产生的信息素，其与LuxR一起激活luxICDABEG操纵子的转录，启动正反馈回路并诱导发光。lux操纵子也受到环境响应调节因子的调节，包括氧化还原响应的ArcA/ArcB系统，其直接抑制培养物中的lux。在这里，我们表明，失活arcA导致增加3 OC 6积累，启动正反馈。在没有正反馈的情况下，arcA介导的发光控制只有102倍，但luxI依赖的正反馈贡献了100倍以上的arcA突变体的净诱导发光。与正反馈的这种压倒一切的重要性相一致，arcA突变体产生的3 OC 6在附近的野生型细胞中诱导发光，克服了它们对照度的arcA抑制。同样，我们发现人工诱导ArcA可以有效地抑制发光之前，但不是之后，正反馈启动。最后，我们表明共生细胞亚群产生的3 OC 6可以诱导共定殖宿主的其他细胞发光。我们的研究结果表明，即使是短暂的损失ArcA介导的调节在一个亚群的细胞可以诱导发光在更广泛的社区。此外，它们表明3 OC 6可以传达有关细胞密度和ArcA/ArcB状态的信息。
Bacterial pheromone signaling is often governed both by environmentally responsive regulators and by positive feedback. This regulatory combination has the potential to coordinate a group response among distinct subpopulations that perceive key environmental stimuli differently. We have explored the interplay between an environmentally responsive regulator and pheromone-mediated positive feedback in intercellular signaling by Vibrio fischeri ES114, a bioluminescent bacterium that colonizes the squid Euprymna scolopes. Bioluminescence in ES114 is controlled in part by N-(3-oxohexanoyl)-L-homoserine lactone (3OC6), a pheromone produced by LuxI that together with LuxR activates transcription of the luxICDABEG operon, initiating a positive feedback loop and inducing luminescence. The lux operon is also regulated by environmentally responsive regulators, including the redox-responsive ArcA/ArcB system, which directly represses lux in culture. Here we show that inactivating arcA leads to increased 3OC6 accumulation to initiate positive feedback. In the absence of positive feedback, arcA-mediated control of luminescence was only ∼2-fold, but luxI-dependent positive feedback contributed more than 100 fold to the net induction of luminescence in the arcA mutant. Consistent with this overriding importance of positive feedback, 3OC6 produced by the arcA mutant induced luminescence in nearby wild-type cells, overcoming their ArcA repression of lux. Similarly, we found that artificially inducing ArcA could effectively repress luminescence before, but not after, positive feedback was initiated. Finally, we show that 3OC6 produced by a subpopulation of symbiotic cells can induce luminescence in other cells co-colonizing the host. Our results suggest that even transient loss of ArcA-mediated regulation in a sub-population of cells can induce luminescence in a wider community. Moreover, they indicate that 3OC6 can communicate information about both cell density and the state of ArcA/ArcB.
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影响因子：
15
作者：
Flickinger, Shane T.;Copeland, Matthew F.;Downes, Eric M.;Braasch, Andrew T.;Tuson, Hannah H.;Eun, Ye-Jin;Weibel, Douglas B.
通讯作者：
Weibel, Douglas B.
DOI：
10.1073/pnas.93.18.9505
发表时间：
1996-09-03
影响因子：
11.1
作者：
Schaefer, AL;Val, DL;Greenberg, EP
通讯作者：
Greenberg, EP
影响因子：
--
作者：
Amy L. Schaefer;B. Hanzelka;M. Parsek;E. Greenberg
通讯作者：
Amy L. Schaefer;B. Hanzelka;M. Parsek;E. Greenberg
接收器模块在保守天冬氨酸残基处的磷酸化/去磷酸化控制大肠杆菌传感器蛋白 ArcB 中组氨酸激酶的转磷酸化活性。
DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Iuchi,S
通讯作者：
Iuchi,S
影响因子：
2.8
作者：
Liang, Weili;Pascual-Montano, Alberto;Benitez, Jorge A.
通讯作者：
Benitez, Jorge A.