Identification of mycobacterial sigma factor binding sites by chromatin immunoprecipitation assays.
Identification of mycobacterial sigma factor binding sites by chromatin immunoprecipitation assays.
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发表时间：
2007
影响因子：
3.2
通讯作者：
Sébastien Rodrigue;Joelle Brodeur;P. Jacques;Alain L. Gervais;R. Brzezinski;L. Gaudreau
中科院分区：
文献类型：
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作者：
Sébastien Rodrigue;Joelle Brodeur;P. Jacques;Alain L. Gervais;R. Brzezinski;L. Gaudreau
结核分枝杆菌和牛分枝杆菌引起的感染在世界各地造成大量死亡、痛苦和损失。然而，人们对这些细菌的基因表达机制知之甚少。在这里，我们使用全基因组定位测定来识别分枝杆菌西格玛因子的直接靶基因。使用牛分枝杆菌BCG对使用无水四环素诱导型启动子表达的Myc标记蛋白进行染色质免疫沉淀测定，并将富集的DNA片段与代表结核分枝杆菌H37Rv基因组的基因间区域的微阵列杂交。通过定量 PCR 验证了几个假定的靶基因。鉴定了 sigma(F)、sigma(C) 和 sigma(K) 相应的转录起始位点，并提出了共有启动子序列。我们的结论得到了体外转录测定结果的支持。我们还检查了每种全酶在西格玛因子基因表达中的作用。我们的结果表明许多西格玛因子是由自动调节启动子表达的。
Mycobacterium tuberculosis and Mycobacterium bovis are responsible for infections that cause a substantial amount of death, suffering, and loss around the world. Still, relatively little is known about the mechanisms of gene expression in these bacteria. Here, we used genome-wide location assays to identify direct target genes for mycobacterial sigma factors. Chromatin immunoprecipitation assays were performed with M. bovis BCG for Myc-tagged proteins expressed using an anhydrotetracycline-inducible promoter, and enriched DNA fragments were hybridized to a microarray representing intergenic regions from the M. tuberculosis H37Rv genome. Several putative target genes were validated by quantitative PCR. The corresponding transcriptional start sites were identified for sigma(F), sigma(C), and sigma(K), and consensus promoter sequences are proposed. Our conclusions were supported by the results of in vitro transcription assays. We also examined the role of each holoenzyme in the expression of sigma factor genes. Our results revealed that many sigma factors are expressed from autoregulated promoters.