Genome-wide expression profiling in Geobacter sulfurreducens:: identification of Fur and RpoS transcription regulatory sites in a relGsu mutant
Genome-wide expression profiling in Geobacter sulfurreducens:: identification of Fur and RpoS transcription regulatory sites in a relGsu mutant
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DOI：
10.1007/s10142-007-0048-5
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发表时间：
2007-07-01
影响因子：
2.9
通讯作者：
Lovley, Derek R.
中科院分区：
文献类型：
--
作者：
Krushkal, Julia;Yan, Bin;Lovley, Derek R.
Rel（Gsu）是在许多生物体中发现的RelA和SpoT蛋白的单一同源物。这些蛋白参与鸟苷3′，5′二焦磷酸（ppGpp）水平的调节，这是细菌在营养限制下生长缓慢和应激反应的信号分子。我们利用从rel（Gsu）缺失突变体的全基因组表达谱中获得的信息来确定rel（Gsu）或ppGpp调节的转录网络中可能涉及的调控位点。与野生型相比，在rel（Gsu）缺失突变体中的差异基因表达可在两种生长条件下获得，即稳态恒化培养和固定期批量培养。这两个数据集的分层聚类分析确定了几组可能共同调控的操作子。通过在这些共调控操作子的上游区域寻找保守基序，我们确定了与Fur和rpos调控位点相似的序列。这些发现表明，硫还原G.中依赖Fur和rpos的基因表达受到Rel（Gsu）介导的信号传导的影响。
Rel(Gsu) is the single Geobacter su furreducens homolog of RelA and SpoT proteins found in many organisms. These proteins are involved in the regulation of levels of guanosine 3', 5' bispyrophosphate, ppGpp, a molecule that signals slow growth and stress response under nutrient limitation in bacteria. We used information obtained from genome-wide expression profiling of the rel(Gsu) deletion mutant to identify putative regulatory sites involved in transcription networks modulated by Rel(Gsu) or ppGpp. Differential gene expression in the rel(Gsu) deletion mutant, as compared to the wild type, was available from two growth conditions, steady state chemostat cultures and stationary phase batch cultures. Hierarchical clustering analysis of these two datasets identified several groups of operons that are likely co-regulated. Using a search for conserved motifs in the upstream regions of these co-regulated operons, we identified sequences similar to Fur- and RpoS-regulated sites. These findings suggest that Fur- and RpoS-dependent gene expression in G. sulfurreducens is affected by Rel(Gsu)-mediated signaling.