Hwang Seung-Ho, Park Jin Hwan, Lee Byungho, Choi Sang Ho
National Research Laboratory of Molecular Microbiology and Toxicology, Center for Food Safety and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea.
Front Microbiol. 2020 Jan 17;10:3063. doi: 10.3389/fmicb.2019.03063. eCollection 2019.
Biofilms provide bacteria with protection from environmental stresses and host immune defenses. The pathogenic marine bacterium forms biofilms and colonizes environmental niches such as oysters. The operon encodes an extracellular matrix protein CabA and the corresponding type I secretion system, which are essential for biofilm and rugose colony development of . In this study, molecular biological analyses revealed the roles of three transcriptional regulators BrpR, BrpT, and BrpS in the regulatory pathway for the operon. BrpR induces and BrpT in turn activates the operon in a sequential cascade, contributing to development of robust biofilm structures. BrpT also activates , but BrpS represses , constituting a negative feedback loop that stabilizes expression. BrpT and BrpS directly bind to specific sequences upstream of , and they constitute a feedforward loop in which BrpT induces and together with BrpS activates , leading to precise regulation of expression. Accordingly, BrpS as well as BrpT plays a crucial role in complete development of rugose colonies. This elaborate network of three transcriptional regulators BrpR, BrpT, and BrpS thus tightly controls regulation, and contributes to successful development of robust biofilms and rugose colonies in .
生物膜为细菌提供了抵御环境压力和宿主免疫防御的保护。这种致病性海洋细菌形成生物膜并定殖于诸如牡蛎等环境生态位。该操纵子编码一种细胞外基质蛋白CabA和相应的I型分泌系统，它们对于该细菌的生物膜和皱纹菌落发育至关重要。在本研究中，分子生物学分析揭示了三种转录调节因子BrpR、BrpT和BrpS在该操纵子调控途径中的作用。BrpR诱导……（此处原文缺失诱导对象），BrpT进而以级联方式激活该操纵子，有助于形成坚固的生物膜结构。BrpT还激活……（此处原文缺失激活对象），但BrpS抑制……（此处原文缺失抑制对象），构成一个稳定……（此处原文缺失稳定对象）表达的负反馈环。BrpT和BrpS直接结合到……（此处原文缺失结合对象）上游的特定序列，它们构成一个前馈环，其中BrpT诱导……（此处原文缺失诱导对象）并与BrpS一起激活……（此处原文缺失激活对象），导致……（此处原文缺失表达对象）表达的精确调控。因此，BrpS以及BrpT在皱纹菌落的完全发育中起着关键作用。BrpR、BrpT和BrpS这三种转录调节因子构成的这个精细网络因此紧密控制……（此处原文缺失控制对象）调控，并有助于该细菌中坚固生物膜和皱纹菌落的成功发育。
