Regulation of the expression of whiB1 in Mycobacterium tuberculosis:: role of cAMP receptor protein
Regulation of the expression of whiB1 in Mycobacterium tuberculosis:: role of cAMP receptor protein
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DOI：
10.1099/mic.0.28924-0
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发表时间：
2006-09-01
期刊：
影响因子：
2.8
通讯作者：
Bishai, William R.
中科院分区：
文献类型：
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作者：
Agarwal, Nisheeth;Raghunand, Tirumalai R.;Bishai, William R.
wbl（whiB样）基因编码放线菌特有的推定转录因子。本研究鉴定了结核分枝杆菌7个wbl基因之一whiB 1（Rv3219c）的启动子元件。结果显示whiB 1由I类cAMP受体蛋白（CRP）依赖性启动子转录，相对于其转录起始点在-58.5处具有CRIP结合位点。体内启动子活性分析和电泳迁移率变动分析表明whiB1的表达确实是由cAMP依赖性结合CRPM（由M.结核病基因Rv3676）至whiB1 5 '非翻译区（5'UTR）。β-半乳糖苷酶基因融合分析显示，在M.只有当存在完整的CRIP结合位点时，才能在添加外源性二丁酸cAMP（一种可扩散的cAMP类似物）时抑制结核病。这些结果表明M.结核病whiB1转录部分地由cAMP水平通过cAMP激活的CRPM与whiB1 5'UTR中的共有CRP结合位点的直接结合来调节。
The wbl (whiB-like) genes encode putative transcription factors unique to actinomycetes. This study characterized the promoter element of one of the seven wbl genes of Mycobacterium tuberculosis, whiB 1 (Rv3219c). The results reveal that whiB 1 is transcribed by a class I-type cAMP receptor protein (CRP)-dependent promoter, harbouring a CRIP-binding site positioned at -58.5 with respect to its transcription start point. In vivo promoter activity analysis and electrophoretic mobility shift assays suggest that the expression of whiB1 is indeed regulated by cAMP-dependent binding of CRPM (encoded by the M. tuberculosis gene Rv3676) to the whiB1 5' untranslated region (5'UTR). beta-Galactosidase gene fusion analysis revealed induction of the whiB1 promoter in M. tuberculosis on addition of exogenous dibutyric cAMP (a diffusible cAMP analogue) only when an intact CRIP-binding site was present. These results indicate that M. tuberculosis whiB1 transcription is regulated in part by cAMP levels via direct binding of cAMP-activated CRPM to a consensus CRP-binding site in the whiB1 5'UTR.