A liquid chromatography-coupled tandem mass spectrometry method for quantitation of cyclic di-guanosine monophosphate

Over 30 years ago, GGDEF domain-containing enzymes were shown to be diguanylate cyclases that produce cyclic di-GMP (cdiG), a second messenger that modulates the key bacterial lifestyle transition from a motile to sessile biofilm-forming state. Since then, the ubiquity of genes encoding GGDEF proteins in bacterial genomes has established the dominance of cdiG signaling in bacteria. However, the observation that proteobacteria encode a large number of GGDEF proteins, nearing 1% of coding sequences in some cases, raises the question of why bacteria need so many GGDEF enzymes. In this study, we reveal that a subfamily of GGDEF enzymes synthesizes the asymmetric signaling molecule cyclic AMP-GMP (cAG or 3′, 3′-cGAMP). This discovery is unexpected because GGDEF enzymes function as symmetric homodimers, with each monomer binding to one substrate NTP. Detailed analysis of the enzyme from Geobacter sulfurreducens showed it is a dinucleotide cyclase capable of switching the major cyclic dinucleotide (CDN) produced based on ATP-to-GTP ratios. We then establish through bioinformatics and activity assays that hybrid CDN-producing and promiscuous substrate-binding (Hypr) GGDEF enzymes are found in other deltaproteobacteria. Finally, we validated the predictive power of our analysis by showing that cAG is present in surface-grown Myxococcus xanthus. This study reveals that GGDEF enzymes make alternative cyclic dinucleotides to cdiG and expands the role of this widely distributed enzyme family to include regulation of cAG signaling.bacterial signaling | surface sensing | second messengers | cyclic dinucleotides | fluorescent biosensor

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“…Cyclic dinucleotides were extracted as described previously (44), with slight modifications. For full procedure, see SI Appendix.…”

Section: Methodsmentioning

confidence: 99%

Hybrid promiscuous (Hypr) GGDEF enzymes produce cyclic AMP-GMP (3′, 3′-cGAMP)

Hallberg

Wang

Wright

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

104

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“…Separation of cell extracts by high-pressure liquid chromatography combined with quantification by mass spectrometry has been the gold standard for measuring c-di-GMP concentrations (17,431,432). Alternative detection and quantification methods for in vitro and in vivo applications are being developed, although the required sensitivity and/or applicability for high-throughput analysis has not yet been reached.…”

Section: Quantification Of C-di-gmpmentioning

confidence: 99%

Cyclic di-GMP: the First 25 Years of a Universal Bacterial Second Messenger

Römling

Galperin

Gomelsky

2013

Microbiol Mol Biol Rev

1,471

1,698

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SUMMARY Twenty-five years have passed since the discovery of cyclic dimeric (3′→5′) GMP (cyclic di-GMP or c-di-GMP). From the relative obscurity of an allosteric activator of a bacterial cellulose synthase, c-di-GMP has emerged as one of the most common and important bacterial second messengers. Cyclic di-GMP has been shown to regulate biofilm formation, motility, virulence, the cell cycle, differentiation, and other processes. Most c-di-GMP-dependent signaling pathways control the ability of bacteria to interact with abiotic surfaces or with other bacterial and eukaryotic cells. Cyclic di-GMP plays key roles in lifestyle changes of many bacteria, including transition from the motile to the sessile state, which aids in the establishment of multicellular biofilm communities, and from the virulent state in acute infections to the less virulent but more resilient state characteristic of chronic infectious diseases. From a practical standpoint, modulating c-di-GMP signaling pathways in bacteria could represent a new way of controlling formation and dispersal of biofilms in medical and industrial settings. Cyclic di-GMP participates in interkingdom signaling. It is recognized by mammalian immune systems as a uniquely bacterial molecule and therefore is considered a promising vaccine adjuvant. The purpose of this review is not to overview the whole body of data in the burgeoning field of c-di-GMP-dependent signaling. Instead, we provide a historic perspective on the development of the field, emphasize common trends, and illustrate them with the best available examples. We also identify unresolved questions and highlight new directions in c-di-GMP research that will give us a deeper understanding of this truly universal bacterial second messenger.

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“…Analysis of the Cyclic Dinucleotide Pools-The concentration of cyclic di-AMP was determined by a liquid chromatographycoupled tandem mass spectrometry method essentially as described previously (28). Briefly, E. coli cultures were grown in LB medium at 37°C.…”

Section: Construction Of Integrative Vectors That Allow the Ectopic Ementioning

confidence: 99%