Transcriptional organization and regulation of the Pseudomonas putida K1 type VI secretion system gene cluster.
Transcriptional organization and regulation of the Pseudomonas putida K1 type VI secretion system gene cluster.
复制标题
转录组织和假单胞菌putida K1型分泌系统基因簇的调节。
DOI：
10.1099/mic.0.001295
复制
发表时间：
2023-01
期刊：
影响因子：
2.8
通讯作者：
Llamas, Maria A.
中科院分区：
文献类型：
--
作者：
Bernal, Patricia;Civantos, Cristina;Pacheco-Sanchez, Daniel;Quesada, Jose M.;Filloux, Alain;Llamas, Maria A.
VI型分泌系统（T6 SS）是一种广泛存在于变形菌中的抗微生物分子武器，为T6 SS阳性微生物提供了竞争优势。最近，三种T6 SS被描述在 恶臭假单胞菌 KT 2440，并且已经显示K1-T6 SS用于胜过广泛的植物病原体，保护植物免受病原体感染。鉴于该系统作为生物控制的强大和创新机制的相关性，了解其表达的过程至关重要。在这里，我们通过实验在K1-T6 SS簇中定义了两个转录单位。一个编码系统的结构成分，并从两个相邻的启动子转录。另一个编码两个假设的蛋白质，系统的尖端和相关的衔接子，以及效应子和同源免疫蛋白，并且它也从两个相邻的启动子转录。这4个启动子均具有σ 70依赖型启动子的典型特征。我们已经研究了在不同条件下，在一些缺乏全球监管机构的突变体的系统的表达。 恶臭假单胞菌 K1-T6 SS在稳定期被诱导表达，但其转录不依赖于稳定σ因子RpoS。事实上，该系统的表达被RpoS间接抑制。此外，它也被RpoN和转录调节因子FleQ抑制，FleQ是一种通常与RpoN结合作用的增强子结合蛋白。重要的是，K1-T6 SS基因簇的表达受到GacS-GacA双组分调节系统（TCS）的正调控，并受到抑制该TCS的RetS传感器激酶的抑制。我们的研究结果确定了一个复杂的调控网络，它通常控制T6 SS的表达， 恶臭假单胞菌 特别是K1-T6 SS，具有控制和操纵在生物控制中高度相关的细菌剂的意义。
The type VI secretion system (T6SS) is an antimicrobial molecular weapon that is widespread in Proteobacteria and offers competitive advantages to T6SS-positive micro-organisms. Three T6SSs have recently been described in Pseudomonas putida KT2440 and it has been shown that one, K1-T6SS, is used to outcompete a wide range of phytopathogens, protecting plants from pathogen infections. Given the relevance of this system as a powerful and innovative mechanism of biological control, it is critical to understand the processes that govern its expression. Here, we experimentally defined two transcriptional units in the K1-T6SS cluster. One encodes the structural components of the system and is transcribed from two adjacent promoters. The other encodes two hypothetical proteins, the tip of the system and the associated adapters, and effectors and cognate immunity proteins, and it is also transcribed from two adjacent promoters. The four identified promoters contain the typical features of σ 70 -dependent promoters. We have studied the expression of the system under different conditions and in a number of mutants lacking global regulators. P. putida K1-T6SS expression is induced in the stationary phase, but its transcription does not depend on the stationary σ factor RpoS. In fact, the expression of the system is indirectly repressed by RpoS. Furthermore, it is also repressed by RpoN and the transcriptional regulator FleQ, an enhancer-binding protein typically acting in conjunction with RpoN. Importantly, expression of the K1-T6SS gene cluster is positively regulated by the GacS–GacA two-component regulatory system (TCS) and repressed by the RetS sensor kinase, which inhibits this TCS. Our findings identified a complex regulatory network that governs T6SS expression in general and P. putida K1-T6SS in particular, with implications for controlling and manipulating a bacterial agent that is highly relevant in biological control.
登录
查看更多内容
DOI：
10.1074/mcp.m113.030502
发表时间：
2013-10
期刊：
Molecular & cellular proteomics : MCP
影响因子：
--
作者：
Fritsch MJ;Trunk K;Diniz JA;Guo M;Trost M;Coulthurst SJ
通讯作者：
Coulthurst SJ
影响因子：
3.2
作者：
Brunet, Yannick R.;Bernard, Christophe S.;Cascales, Eric
通讯作者：
Cascales, Eric
影响因子：
10.5
作者：
Battesti A;Majdalani N;Gottesman S
通讯作者：
Gottesman S
影响因子：
5.1
作者：
Borrero de Acuna, Jose Manuel;Bernal, Patricia
通讯作者：
Bernal, Patricia
DOI：
10.1038/ismej.2016.169
发表时间：
2017-04
期刊：
The ISME journal
影响因子：
--
作者：
Bernal P;Allsopp LP;Filloux A;Llamas MA
通讯作者：
Llamas MA