Transcriptional downregulation of agr expression in Staphylococcus aureus during growth in human serum can be overcome by constitutively active mutant forms of the sensor kinase AgrC.
Transcriptional downregulation of agr expression in Staphylococcus aureus during growth in human serum can be overcome by constitutively active mutant forms of the sensor kinase AgrC.
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DOI：
10.1111/1574-6968.12309
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发表时间：
2013-12
影响因子：
2.1
通讯作者：
Wigneshweraraj S
中科院分区：
文献类型：
--
作者：
James EH;Edwards AM;Wigneshweraraj S
几乎所有金黄色葡萄球菌病毒的表达的时间和细胞密度依赖性调节都处于 agr（辅助基因调节）操纵子的控制之下。 agr 操纵子的表达受到 AgrA/C 双组分反应调节器/传感器激酶对的转录调节。菌血症是一种由耐甲氧西林金黄色葡萄球菌 (MRSA) 引起的常见综合征，在菌血症期间，agr 表达的转录下调归因于人血清成分载脂蛋白 B 对群体信号分子自诱导肽 (AIP) 的隔离，这是对感染的先天免疫反应的一部分。然而，尚不清楚在人血清中生长期间agr表达的转录下调是否另外受到直接或间接影响agr操纵子启动子转录的转录调节蛋白的调节。在这里，我们使用金黄色葡萄球菌中 agr 表达的染色体荧光报告基因，表明可以使用 AgrC 的组成型活性突变体形式来克服人血清中 agr 表达的转录下调。因此，AIP 的隔离似乎可能是宿主先天免疫反应在转录水平限制 agr 表达以维持宿主-病原体平衡以实现非侵入性结果的唯一机制。
The temporal and cell density-dependent regulation of expression of virtually all the Staphylococcus aureus virulon is under the control of the agr (accessory gene regulatory) operon. The expression of the agr operon is subject to transcriptional regulation by the AgrA/C two-component response regulator/sensor kinase pair. During bacteraemia, a frequent syndrome caused by methicillin-resistant S. aureus (MRSA), the transcriptional downregulation of agr expression has been attributed to the sequestration of the quorum-signalling molecule auto-inducing peptide (AIP) by the human serum component apolipoprotein B as part of an innate immune response to infection. However, it is not known whether transcriptional downregulation of agr expression during growth in human serum is additionally subjected to regulation by transcription regulatory proteins that either directly or indirectly affect transcription from the agr operon promoters. Here, using chromosomal fluorescence reporters of agr expression in S. aureus, we show that the transcriptional downregulation of agr expression in human serum can be overcome using constitutive active mutant forms of AgrC. Therefore, it seems that the sequestration of the AIP is likely to be the only mechanism by which the host innate immune response limits agr expression at the transcriptional level to maintain the host–pathogen balance towards a noninvasive outcome.
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影响因子：
3.2
作者：
Wuster, Arthur;Babu, M. Madan
通讯作者：
Babu, M. Madan
影响因子：
4.9
作者：
Chong, Yong Pil;Kim, Eun Sil;Kim, Yang Soo
通讯作者：
Kim, Yang Soo
影响因子：
6.4
作者：
Fey PD;Endres JL;Yajjala VK;Widhelm TJ;Boissy RJ;Bose JL;Bayles KW
通讯作者：
Bayles KW
DOI：
10.3390/s130405130
发表时间：
2013-04-18
期刊：
Sensors (Basel, Switzerland)
影响因子：
--
作者：
Gray B;Hall P;Gresham H
通讯作者：
Gresham H
影响因子：
5.6
作者：
Reynolds, Jonathan;Wigneshweraraj, Sivaramesh
通讯作者：
Wigneshweraraj, Sivaramesh