Mapping the CgrA regulon of Rhodospirillum centenum reveals a hierarchal network controlling Gram-negative cyst development.
Mapping the CgrA regulon of Rhodospirillum centenum reveals a hierarchal network controlling Gram-negative cyst development.
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DOI：
10.1186/s12864-015-2248-z
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发表时间：
2015-12-16
期刊：
影响因子：
4.4
通讯作者：
Bauer CE
中科院分区：
文献类型：
--
作者：
Dong Q;Fang M;Roychowdhury S;Bauer CE
几种革兰氏阴性菌经过发育，形成代谢休眠的抗干燥孢囊。最近对孢囊发育的分析表明，当细胞从营养体转变为孢囊形式时，~ 20%的百蕊杜鹃转录组经历表达的时间变化。还已经确定，囊肿形成的一个触发因素是信号核苷酸3 '，5'-环鸟苷一磷酸（cGMP）的合成，其被称为CgrA的分解代谢物阻遏蛋白的同源物感知。在cGMP存在下，CgrA启动基因表达级联，导致囊肿的发展。在这项研究中，我们使用RNA-seq和染色质免疫沉淀（ChIP-Seq）技术来定义CgrA-cGMP调节子。我们的研究结果表明，破坏CgrA导致258个基因的表达改变，其中131个先前已报道参与囊肿的发展。与转录组数据相结合的ChIP-seq分析还表明，CgrA直接调节许多sigma因子和转录因子的表达，其中几种已知参与囊肿细胞发育。该分析揭示了CgrA结合位点上游的许多发育调控基因，包括许多转录因子和信号转导组件的存在。因此，CgrA通过启动诱导包囊形成基因的时间表达的下游转录因子的分级级联，起包囊形成的主控制器的作用。本文的在线版本（doi：10.1186/s12864-015-2248-z）包含补充材料，可供授权用户使用。
Several Gram-negative species undergo development leading to the formation of metabolically dormant desiccation resistant cysts. Recent analysis of cyst development has revealed that ~20 % of the Rhodospirillum centenum transcriptome undergo temporal changes in expression as cells transition from vegetative to cyst forms. It has also been established that one trigger for cyst formation is the synthesis of the signaling nucleotide 3‘, 5‘- cyclic guanosine monophosphate (cGMP) that is sensed by a homolog of the catabolite repressor protein called CgrA. CgrA in the presence of cGMP initiate a cascade of gene expression leading to the development of cysts. In this study, we have used RNA-seq and chromatin immunoprecipitation (ChIP-Seq) techniques to define the CgrA-cGMP regulon. Our results indicate that disruption of CgrA leads to altered expression of 258 genes, 131 of which have been previously reported to be involved in cyst development. ChIP-seq analysis combined with transcriptome data also demonstrates that CgrA directly regulates the expression of numerous sigma factors and transcription factors several of which are known to be involved in cyst cell development. This analysis reveals the presence of CgrA binding sites upstream of many developmentally regulated genes including many transcription factors and signal transduction components. CgrA thus functions as master controller of the cyst development by initiating a hierarchal cascade of downstream transcription factors that induces temporal expression of encystment genes. The online version of this article (doi:10.1186/s12864-015-2248-z) contains supplementary material, which is available to authorized users.