Direct regulation of the natural competence regulator gene tfoX by cyclic AMP (cAMP) and cAMP receptor protein (CRP) in Vibrios.
Direct regulation of the natural competence regulator gene tfoX by cyclic AMP (cAMP) and cAMP receptor protein (CRP) in Vibrios.
复制标题
弧菌中环AMP（cAMP）和cAMP受体蛋白（CRP）对自然能力调节基因tfoX的直接调节
DOI：
10.1038/srep14921
复制
发表时间：
2015-10-07
影响因子：
4.6
通讯作者：
Liang W
中科院分区：
文献类型：
--
作者：
Wu R;Zhao M;Li J;Gao H;Kan B;Liang W
TfoX (Sxy) and CRP are two important competence activators. The link betweentfoXand CRP has been shown inH. influenzabut lacking evidence of direct interaction. Recently a Sxy-dependent CRP (CRP-S) site autoregulating Sxy was reported inE. coli. Here, we show that the cAMP-CRP complex transcriptionally regulatestfoXexpression through multiple canonical CRP (CRP-N) sites inVibrios.This conclusion is supported by an analysis of thetfoXmRNA levels andtfoXtranscriptional reporter fusions. The reduced expression oftfoXVCwas restored by trans-complementation ofcrpin ∆crpand by exogenous cAMP in ∆cya. A promoter deletion analysis and the site-directed mutagenesis of the putative CRP-N sites revealed the presence of two functional CRP-N sites. The direct binding of cAMP-CRP to thetfoXVCpromoter was demonstrated by EMSA assays. Additionally, the transcriptional start site (TSS) oftfoXVFinV. fluvialiswas determined and −10/−35 regions were predicted. Further comparison of thetfoXpromoter inVibriosrevealed the existence of similar −10 motifs and putative CRP-N sites, indicating the conserved mechanism of CRP regulation ontfoX. Our study demonstrates the direct binding of the cAMP-CRP complex totfoXpromoter and broadens the understanding of the molecular mechanism regulatingtfoXinVibrios.
