Functional Characterization of Core Components of the Bacillus subtilis Cyclic-Di-GMP Signaling Pathway

Gao, Xiaohui; Mukherjee, Sampriti; Matthews, Paige M.; Hammad, Loubna A.; Kearns, Daniel B.; Dann, Charles E.

doi:10.1128/jb.00373-13

Cited by 80 publications

(162 citation statements)

References 63 publications

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“…The majority of diguanylate cyclases have been identified in Gram-negative bacteria, whereas diadenylate cyclases have been reported mostly in Gram-positive bacteria. The presence of c-di-GMP signaling in Gram-positive bacteria has been directly demonstrated only in B. subtilis (55,56) and the spore-forming, obligate anaerobe Clostridium difficile (57). We were unable to find any GGDEF motif in S. pneumoniae proteins.…”

Section: Discussionmentioning

confidence: 47%

Two DHH Subfamily 1 Proteins in Streptococcus pneumoniae Possess Cyclic Di-AMP Phosphodiesterase Activity and Affect Bacterial Growth and Virulence

et al. 2013

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c Cyclic di-AMP (c-di-AMP) and cyclic di-GMP (c-di-GMP) are signaling molecules that play important roles in bacterial biology and pathogenesis. However, these nucleotides have not been explored in Streptococcus pneumoniae, an important bacterial pathogen. In this study, we characterized the c-di-AMP-associated genes of S. pneumoniae. The results showed that SPD_1392 (DacA) is a diadenylate cyclase that converts ATP to c-di-AMP. Both SPD_2032 (Pde1) and SPD_1153 (Pde2), which belong to the DHH subfamily 1 proteins, displayed c-di-AMP phosphodiesterase activity. Pde1 cleaved c-di-AMP into phosphoadenylyl adenosine (pApA), whereas Pde2 directly hydrolyzed c-di-AMP into AMP. Additionally, Pde2, but not Pde1, degraded pApA into AMP. Our results also demonstrated that both Pde1 and Pde2 played roles in bacterial growth, resistance to UV treatment, and virulence in a mouse pneumonia model. These results indicate that c-di-AMP homeostasis is essential for pneumococcal biology and disease.

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Section: Discussionmentioning

confidence: 47%

Two DHH Subfamily 1 Proteins in Streptococcus pneumoniae Possess Cyclic Di-AMP Phosphodiesterase Activity and Affect Bacterial Growth and Virulence

et al. 2013

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“…The c-di-GMP signaling molecule negatively regulates the flagellar motility of a large number of bacteria by diverse mechanisms, including transcriptional, posttranscriptional, and posttranslational control (36)(37)(38)(39)(40)(41)(42)(43)(44). In C. difficile, regulation of motility by c-di-GMP likely occurs through a direct effect of c-di-GMP on the expression of a putative large flagellar operon, the flgB operon, via a c-di-GMP riboswitch (45).…”

mentioning

confidence: 99%

The Second Messenger Cyclic Di-GMP Regulates Clostridium difficile Toxin Production by Controlling Expression of sigD

et al. 2013

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The Gram-positive obligate anaerobe Clostridium difficile causes potentially fatal intestinal diseases. How this organism regulates virulence gene expression is poorly understood. In many bacterial species, the second messenger cyclic di-GMP (c-di-GMP) negatively regulates flagellar motility and, in some cases, virulence. c-di-GMP was previously shown to repress motility of C. difficile. Recent evidence indicates that flagellar gene expression is tightly linked with expression of the genes encoding the two C. difficile toxins TcdA and TcdB, which are key virulence factors for this pathogen. Here, the effect of c-di-GMP on expression of the toxin genes tcdA and tcdB was determined, and the mechanism connecting flagellar and toxin gene expressions was examined. In C. difficile, increasing c-di-GMP levels reduced the expression levels of tcdA and tcdB, as well as that of tcdR, which encodes an alternative sigma factor that activates tcdA and tcdB expression. We hypothesized that the C. difficile orthologue of the flagellar alternative sigma factor SigD (FliA; 28 ) mediates regulation of toxin gene expression in response to c-di-GMP. Indeed, ectopic expression of sigD in C. difficile resulted in increased expression levels of tcdR, tcdA, and tcdB. Furthermore, sigD expression enhanced toxin production and increased the cytopathic effect of C. difficile on cultured fibroblasts. Finally, evidence is provided that SigD directly activates tcdR expression and that SigD cannot activate tcdA or tcdB expression independent of TcdR. Taken together, these data suggest that SigD positively regulates toxin genes in C. difficile and that c-di-GMP can inhibit both motility and toxin production via SigD, making this signaling molecule a key virulence gene regulator in C. difficile.

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“…Two recent studies have addressed the role of c-di-GMP in biofilm formation in B. subtilis (58,59). However, whereas one report suggested an implication of c-di-GMP in biofilm formation (58), the other excluded this possibility.…”

Section: Discussionmentioning

confidence: 92%

“…We considered the secondary messenger cyclic di-GMP, which has been shown to influence biofilm formation in various other bacteria (57). Recently, both c-di-GMP and c-di-AMP have been shown to be present in B. subtilis (31,(58)(59)(60)(61)(62), and there are several c-di-GMP and c-di-AMP synthases and hydrolases in the B. subtilis genome, strongly suggesting an important physiological role for these molecules (42). To test the involvement of YmdB in the homeostasis of these molecules, we performed two sets of experiments.…”

Section: Resultsmentioning

confidence: 99%

The YmdB Phosphodiesterase Is a Global Regulator of Late Adaptive Responses in Bacillus subtilis

Diethmaier

Newman

Kovács³

et al. 2013

Journal of Bacteriology

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dBacillus subtilis mutants lacking ymdB are unable to form biofilms, exhibit a strong overexpression of the flagellin gene hag, and are deficient in SlrR, a SinR antagonist. Here, we report the functional and structural characterization of YmdB, and we find that YmdB is a phosphodiesterase with activity against 2=,3=-and 3=,5=-cyclic nucleotide monophosphates. The structure of YmdB reveals that the enzyme adopts a conserved phosphodiesterase fold with a binuclear metal center. Mutagenesis of a catalytically crucial residue demonstrates that the enzymatic activity of YmdB is essential for biofilm formation. The deletion of ymdB affects the expression of more than 800 genes; the levels of the D -dependent motility regulon and several sporulation genes are increased, and the levels of the SinR-repressed biofilm genes are decreased, confirming the role of YmdB in regulating late adaptive responses of B. subtilis.

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Functional Characterization of Core Components of the Bacillus subtilis Cyclic-Di-GMP Signaling Pathway

Cited by 80 publications

References 63 publications

Two DHH Subfamily 1 Proteins in Streptococcus pneumoniae Possess Cyclic Di-AMP Phosphodiesterase Activity and Affect Bacterial Growth and Virulence

Two DHH Subfamily 1 Proteins in Streptococcus pneumoniae Possess Cyclic Di-AMP Phosphodiesterase Activity and Affect Bacterial Growth and Virulence

The Second Messenger Cyclic Di-GMP Regulates Clostridium difficile Toxin Production by Controlling Expression of sigD

The YmdB Phosphodiesterase Is a Global Regulator of Late Adaptive Responses in Bacillus subtilis

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