AphA and LuxR/HapR reciprocally control quorum sensing in vibrios
AphA and LuxR/HapR reciprocally control quorum sensing in vibrios
复制标题
DOI：
10.1101/gad.2015011
复制
发表时间：
2011-02-15
影响因子：
10.5
通讯作者：
Bassler, Bonnie L.
中科院分区：
文献类型：
--
作者：
Rutherford, Steven T.;van Kessel, Julia C.;Bassler, Bonnie L.
细菌在进行个体行为的时期和进行群体行为的时期之间循环。这些转换是由称为群体感应的细胞间通信过程控制的，其中细胞外信号分子（称为自诱导物（AI））被释放，积累并被一组细菌同步检测。AI检测导致整个社区的基因表达变化，使细菌能够共同执行生物发光，生物膜形成和毒力因子产生等行为。在这项研究中，我们表明，转录因子AphA是一个主调节器的群体感应，在低细胞密度（LCD）的哈维氏弧菌和霍乱弧菌。相比之下，LuxR（哈维氏弧菌）/HapR（霍乱弧菌）是在高细胞密度（HCD）下工作的主调节因子。在LCD中，多余的小非编码RNA（sRNA）激活AphA的产生，AphA和sRNA抑制LuxR/HapR的产生。相反，在HCD中，LuxR/HapR抑制aphA。该网络架构确保LCD处的最大AphA产量和HCD处的最大LuxR/HapR产量。微阵列分析表明，在哈维氏弧菌中，有300个基因受AphA在LCD上的调控，其中一个子集也受LuxR的调控。我们建议AphA和LuxR/HapR的倒数梯度分别建立群体感应LCD和HCD基因表达模式。
Bacteria cycle between periods when they perform individual behaviors and periods when they perform group behaviors. These transitions are controlled by a cell-cell communication process called quorum sensing, in which extracellular signal molecules, called autoinducers (AIs), are released, accumulate, and are synchronously detected by a group of bacteria. AI detection results in community-wide changes in gene expression, enabling bacteria to collectively execute behaviors such as bioluminescence, biofilm formation, and virulence factor production. In this study, we show that the transcription factor AphA is a master regulator of quorum sensing that operates at low cell density (LCD) in Vibrio harveyi and Vibrio cholerae. In contrast, LuxR (V. harveyi)/HapR (V. cholerae) is the master regulator that operates at high cell density (HCD). At LCD, redundant small noncoding RNAs (sRNAs) activate production of AphA, and AphA and the sRNAs repress production of LuxR/HapR. Conversely, at HCD, LuxR/HapR represses aphA. This network architecture ensures maximal AphA production at LCD and maximal LuxR/HapR production at HCD. Microarray analyses reveal that 300 genes are regulated by AphA at LCD in V. harveyi, a subset of which is also controlled by LuxR. We propose that reciprocal gradients of AphA and LuxR/HapR establish the quorum-sensing LCD and HCD gene expression patterns, respectively.