The <i>Escherichia coli</i> cAMP receptor protein (CRP) represses the <i>Rhizobium meliloti dctA</i> promoter in a cAMP‐dependent fashion

Wang, Yi‐Ping; Giblin, Linda; Boesten, Bert; O’Gara, Fergal

doi:10.1111/j.1365-2958.1993.tb01569.x

Cited by 19 publications

(26 citation statements)

References 39 publications

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“…The inhibitory effect of activated CRP on Pu remains when its cognate activator XylR is replaced by another member in the NtrC family (such as NtrC-phosphate, Figure 4). These results are in agreement with our previous observations at other σ 54 -dependent promoters [20], [22]. However, to our surprise, it was observed that such down-regulation is probably occurring through CRP-cAMP-mediated conformational change of the closed complex at Pu promoter in vivo (Figure 5).…”

Section: Discussionsupporting

confidence: 93%

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CRP-Cyclic AMP Dependent Inhibition of the Xylene-Responsive σ54-Promoter Pu in Escherichia coli

et al. 2014

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The expression of σ54-dependent Pseudomonas putida Pu promoter is activated by XylR activator when cells are exposed to a variety of aromatic inducers. In this study, the transcriptional activation of the P. putida Pu promoter was recreated in the heterologous host Escherichia coli. Here we show that the cAMP receptor protein (CRP), a well-known carbon utilization regulator, had an inhibitory effect on the expression of Pu promoter in a cAMP-dependent manner. The inhibitory effect was not activator specific. In vivo KMnO4 and DMS footprinting analysis indicated that CRP-cAMP poised the RNA polymerase at Pu promoter, inhibiting the isomerization step of the transcription initiation even in the presence of an activator. Therefore, the presence of PTS-sugar, which eliminates cAMP, could activate the poised RNA polymerase at Pu promoter to transcribe. Moreover, the activation region 1 (AR1) of CRP, which interacts directly with the αCTD (C-terminal domain of α-subunit) of RNA polymerase, was found essential for the CRP-mediated inhibition at Pu promoter. A model for the above observations is discussed.

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Section: Discussionsupporting

confidence: 93%

“…Previous studies showed that CRP-cAMP down-regulated the σ 54 -dependent dctA and glnA p2 promoters in Escherichia coli [20]–[22]. Two mechanisms are involved for the CRP-mediated inhibition of the expression of glnA p2 promoter [23].…”

Section: Introductionmentioning

confidence: 97%

CRP-Cyclic AMP Dependent Inhibition of the Xylene-Responsive σ54-Promoter Pu in Escherichia coli

et al. 2014

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“…Transcriptome data from this work revealed that the expression of smb20436, a putative nitrate transporter gene which might also be driven by a σ 54 -dependent promoter (cited from http://www.promscan.uklinux.net), was upshifted 2.5-fold by exogenous cAMP. In E. coli, cAMP significantly downregulates the expression of glnAp2, K. pneumoniae nif promoters and S. meliloti dctA promoter [5,22,23] . Furthermore, the expression of S. meliloti glnII and glnK promoters is also downregulated by cAMP in E. coli (data not shown).…”

Section: Discussionmentioning

confidence: 99%

Exogenous cAMP upregulates the expression of glnII and glnK-amtB genes in Sinorhizobium meliloti 1021

Tian

Mao

et al. 2006

CHINESE SCI BULL

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The existence of multiple adenylate cyclase encoding genes implies the importance of cAMP in Sinorhizobium meliloti 1021. In this study, as a pioneer step of understanding cAMP roles, microarray analysis on S. meliloti was carried out for the function of exogenous cAMP. To our surprise, the result showed that the transcriptions of glnII and glnK genes were significantly upshifted in the presence of exogenous cAMP in S. meliloti. This phenomenon is further confirmed in S. meliloti that the expression of either glnII or glnK promoter-lacZ translational fusion is higher in the presence of exogenous cAMP. Therefore, for the first time, we have identified genes from S. meliloti whose expression is activated by cAMP. The potential physiological role of upregulation of glnII and glnK by cAMP is discussed.

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“…On the other hand, CRP is capable of regulating genes transcribed by a variety of sigma factors such as 70 , 38 , 32 , and 24 (25). Recently, however, it has been shown that E 54 promoters can be responsive to CRP, since the 54 -dependent promoters dctA and glnAP2 are down-regulated via an interaction between E 54 and the cAMP-CRP complex (46,48,49). The authors proposed a regulatory role for the cAMP-CRP complex as a switch balancing carbon metabolism and nitrogen assimilation in E. coli by cAMP-dependent repression of a 54 -dependent promoter via CRP.…”

Section: Discussionmentioning

confidence: 99%

Catabolite Repression of the Propionate Catabolic Genes inEscherichia coliandSalmonella enterica: Evidence for Involvement of the Cyclic AMP Receptor Protein

2005

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Previous studies with Salmonella enterica serovar Typhimurium LT2 demonstrated that transcriptional activation of the prpBCDE operon requires the function of transcription factor PrpR, sigma-54, and IHF. In this study, we found that transcription from the prpBCDE and prpR promoters was down-regulated by the addition of glucose or glycerol, indicating that these genes may be regulated by the cyclic AMP (cAMP)-cAMP receptor protein (CRP) complex. Targeted mutagenesis of a putative CRP-binding site in the promoter region between prpR and prpBCDE suggested that these genes are under the control of CRP. Furthermore, cells with defects in cya or crp exhibited reduced transcriptional activation of prpR and prpBCDE in Escherichia coli. These results demonstrate that propionate metabolism is subject to catabolite repression by the global transcriptional regulator CRP and that this regulation is effected through control of both the regulator gene prpR and the prpBCDE operon itself. The unique properties of the regulation of these two divergent promoters may have important implications for mechanisms of CRP-dependent catabolite repression acting in conjunction with a member of the sigma-54 family of transcriptional activators.In Escherichia coli, glucose controls utilization of alternative carbon sources by regulating gene expression in response to glucose depletion (8,19,21). Transcriptional regulation is modulated by the level of cyclic AMP (cAMP) synthesized by the membrane-bound adenylate cyclase and cAMP receptor protein (CRP), a global transcriptional regulator. Phosphorylated EIIA Glc , an intermediate in the phosphorylation cascade of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) for the uptake of glucose, is thought to stimulate adenylate cyclase. As a consequence, the active cAMP-CRP complex binds to specific DNA sites located at or upstream of CRP-dependent promoters. Binding of cAMP-CRP to these DNA sites modulates transcription initiation by RNA polymerase (RNAP). In addition, recent studies on catabolite repression caused by non-PTS sugars such as glucose-6-phosphate or gluconate concluded that it is the amount of CRP, as well as cAMP, that is altered in response to non-PTS sugars (14,16,44). Interestingly, Eppler et al. (9) proposed that glycerol-3-phosphate or glycerol also causes catabolite repression by interference with the stimulation of adenylate cyclase by EIIA Glc -P. The cluster of genes required for the catabolism of propionate was first identified in and characterized for Salmonella enterica serovar Typhimurium (12, 15), and a closely related gene cluster was found in E. coli during the sequencing of this bacterium (1). These genes constitute a locus composed of two divergently transcribed units. One unit is the single gene prpR, which encodes a member of the sigma-54 ( 54 )-dependent activator family (32,40). The second transcriptional unit contains the prpBCDE operon, which encodes the enzymes for propionate metabolism (also known as the 2-methylcitrate pathway), allowing gro...

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The Escherichia coli cAMP receptor protein (CRP) represses the Rhizobium meliloti dctA promoter in a cAMP‐dependent fashion

Cited by 19 publications

References 39 publications

CRP-Cyclic AMP Dependent Inhibition of the Xylene-Responsive σ54-Promoter Pu in Escherichia coli

CRP-Cyclic AMP Dependent Inhibition of the Xylene-Responsive σ54-Promoter Pu in Escherichia coli

Exogenous cAMP upregulates the expression of glnII and glnK-amtB genes in Sinorhizobium meliloti 1021

Catabolite Repression of the Propionate Catabolic Genes inEscherichia coliandSalmonella enterica: Evidence for Involvement of the Cyclic AMP Receptor Protein

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