Beijing 302 Hospital, Beijing 100039, China; State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
Int J Food Microbiol. 2013 Sep 16;166(3):458-63. doi: 10.1016/j.ijfoodmicro.2013.07.008. Epub 2013 Jul 17.
Vibrio parahaemolyticus AphA and OpaR are the two master regulators of quorum sensing (QS) that are abundantly produced and operate at low cell density (LCD) and high cell density (HCD), respectively, with an outcome of reciprocally gradient production of these two proteins with transition between LCD and HCD. The cpsQ-mfpABC gene cluster is transcribed as two operons cpsQ-mfpABC and mfpABC in V. parahaemolyticus. MfpABC is a putative membrane fusion transporter that contributes to biofilm development. CpsQ is a c-di-GMP-binding regulator that activates the expression of capsular polysaccharide genes and mfpABC and, thus, induces biofilm development. As shown in this study, OpaR and AphA bind to the promoter region of mfpABC to enhance and repress its transcription, respectively. In contrast, the positive and negative regulation of cpsQ-mfpABC by AphA and OpaR, respectively, achieves probably through acting of AphA or OpaR on additional unknown regulator(s) of cpsQ-mfpABC. The transcriptional levels of cpsQ-mfpABC and mfpABC enhance gradually with transition from LCD to HCD due to the above reciprocal regulatory action of OpaR and AphA. Data presented here present a novel paradigm of combined action of the two master QS regulators in controlling expression of the QS regulon members.
副溶血弧菌 AphA 和 OpaR 是两种主要的群体感应（QS）调节因子，分别在低细胞密度（LCD）和高细胞密度（HCD）下大量产生并发挥作用，其结果是这两种蛋白质的产量呈相互梯度变化，随着 LCD 和 HCD 之间的转换而变化。在副溶血弧菌中，cpsQ-mfpABC 基因簇作为两个操纵子 cpsQ-mfpABC 和 mfpABC 转录。MfpABC 是一种假定的膜融合转运蛋白，有助于生物膜的发展。CpsQ 是一种 c-di-GMP 结合调节剂，它激活荚膜多糖基因和 mfpABC 的表达，从而诱导生物膜的发展。如本研究所示，OpaR 和 AphA 分别结合 mfpABC 的启动子区域，以增强和抑制其转录。相反，AphA 和 OpaR 分别对 cpsQ-mfpABC 的正、负调节可能是通过 AphA 或 OpaR 对 cpsQ-mfpABC 的其他未知调节因子的作用实现的。由于 OpaR 和 AphA 的上述相互调节作用，cpsQ-mfpABC 和 mfpABC 的转录水平随着从 LCD 到 HCD 的转变而逐渐增强。这里呈现的数据提出了一种新的范例，即两种主要的 QS 调节因子在控制 QS 调节子成员的表达方面的联合作用。
