Early activation of quorum sensing in Pseudomonas aeruginosa reveals the architecture of a complex regulon.
Early activation of quorum sensing in Pseudomonas aeruginosa reveals the architecture of a complex regulon.
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DOI：
10.1186/1471-2164-8-287
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发表时间：
2007-08-22
期刊：
影响因子：
4.4
通讯作者：
Greenberg EP
中科院分区：
文献类型：
--
作者：
Schuster M;Greenberg EP
铜绿假单胞菌基因表达的群体感应调控是复杂的。两个相互连接的酰基-高丝氨酸内酯（酰基-HSL）信号受体对，3-氧代-十二烷酰基-HSL-LasR和丁酰基-HSL-RhlR，调节超过300个基因。大多数基因的诱导在铜绿假单胞菌在复杂培养基中生长期间被延迟，不能通过添加外源信号来推进，并且需要额外的调节组分。这些晚期基因中的许多可以通过使用特定的培养基条件在早期添加信号来诱导。虽然有几个因素超调节的群体受体，其他人可能共同调节目标启动子或可能影响转录后表达。为了更好地理解超调节和共调节对群体感应基因表达的贡献，以及更好地理解群体感应网络的一般结构，我们异位表达了两种受体（在其同源信号的存在下）和另一种影响群体感应的组分，即稳定相sigma因子RpoS，在生长早期。我们通过微阵列和实时PCR分析确定了对靶基因表达的影响。我们的研究结果表明，许多靶基因（如lasB和hcnABC）直接响应受体蛋白水平。大多数基因（如lasA，lecA和phnAB），然而，没有显着影响，虽然这些基因中至少有一些直接调节群体感应。大多数由RhlR推进的启动子似乎被直接调节，这使得我们能够构建RhlR共有序列。许多群体感应靶基因在生长早期对受体蛋白水平的直接反应证实了超调节在群体感应基因表达中的作用。大多数靶基因的诱导不受信号或受体蛋白水平的影响的观察结果表明，靶启动子由其他转录因子共同调节，或者表达受转录后控制。这种结构允许多个信号通路的整合，导致需要“群体”的群体反应，但在其他方面高度适应和接受环境条件。
Quorum-sensing regulation of gene expression in Pseudomonas aeruginosa is complex. Two interconnected acyl-homoserine lactone (acyl-HSL) signal-receptor pairs, 3-oxo-dodecanoyl-HSL-LasR and butanoyl-HSL-RhlR, regulate more than 300 genes. The induction of most of the genes is delayed during growth of P. aeruginosa in complex medium, cannot be advanced by addition of exogenous signal, and requires additional regulatory components. Many of these late genes can be induced by addition of signals early by using specific media conditions. While several factors super-regulate the quorum receptors, others may co-regulate target promoters or may affect expression posttranscriptionally. To better understand the contributions of super-regulation and co-regulation to quorum-sensing gene expression, and to better understand the general structure of the quorum sensing network, we ectopically expressed the two receptors (in the presence of their cognate signals) and another component that affects quorum sensing, the stationary phase sigma factor RpoS, early in growth. We determined the effect on target gene expression by microarray and real-time PCR analysis. Our results show that many target genes (e.g. lasB and hcnABC) are directly responsive to receptor protein levels. Most genes (e.g. lasA, lecA, and phnAB), however, are not significantly affected, although at least some of these genes are directly regulated by quorum sensing. The majority of promoters advanced by RhlR appeared to be regulated directly, which allowed us to build a RhlR consensus sequence. The direct responsiveness of many quorum sensing target genes to receptor protein levels early in growth confirms the role of super-regulation in quorum sensing gene expression. The observation that the induction of most target genes is not affected by signal or receptor protein levels indicates that either target promoters are co-regulated by other transcription factors, or that expression is controlled posttranscriptionally. This architecture permits the integration of multiple signaling pathways resulting in quorum responses that require a "quorum" but are otherwise highly adaptable and receptive to environmental conditions.
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影响因子：
3.2
作者：
Pesci, EC;Pearson, JP;Iglewski, BH
通讯作者：
Iglewski, BH
影响因子：
2.6
作者：
Hoang, TT;Kutchma, AJ;Schweizer, HP
通讯作者：
Schweizer, HP
影响因子：
3.2
作者：
Baynham, PJ;Ramsey, DM;Wozniak, DJ
通讯作者：
Wozniak, DJ
影响因子：
3.2
作者：
Pearson, JP;Pesci, EC;Iglewski, BH
通讯作者：
Iglewski, BH
DOI：
10.1073/pnas.97.16.8789
发表时间：
2000-08-01
影响因子：
11.1
作者：
Parsek, MR;Greenberg, EP
通讯作者：
Greenberg, EP