Detoxification of the explosive 2,4,6‐trinitrotoluene in Arabidopsis: discovery of bifunctional <i>O</i>‐ and <i>C</i>‐glucosyltransferases

García-Carmona, Francisco; Lorenz, Astrid; Larson, Tony R.; Graham, Ian A.; Bowles, Dianna J.; Rylott, Elizabeth L.; Bruce, Neil C.

doi:10.1111/j.1365-313x.2008.03653.x

Cited by 137 publications

(119 citation statements)

References 37 publications

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“…While the ability to conjugate these synthetic compounds is not the endogenous role of t class GSTs, it is possible that these xenobiotics might share chemical similarities with endogenous substrates. Gandia-Herrero et al, 2008) and corroborative qPCR data on Arabidopsis plants treated with TNT. The qPCR results were normalized to the ACTIN2 gene, and the results are means of five biological replicates 6 SE.…”

Section: Activity Of Recombinant Gstsmentioning

confidence: 71%

“…Following production, GST conjugates are imported to the vacuole, and two glutathione conjugate ATP-binding cassette transporters, Multidrug resistance-associated protein1 (MRP1) and MRP2, are up-regulated in Arabidopsis in response to TNT (2-and 5-fold respectively; Gandia-Herrero et al, 2008). After import, studies on herbicide detoxification by GSTs showed that further processing occurs, releasing cysteinyl-Gly, g-glutamyl-Cys, and Cys derivatives (Grzam et al, 2006; Ohkama-Ohtsu Table II.…”

Section: Glutathione-tnt Productsmentioning

confidence: 99%

“…Following microarray analysis of TNT-treated Arabidopsis plants (Gandia-Herrero et al, 2008), eight up-regulated GSTs, all in the t class (GST-U1, GST-U3, GST-U4, GST-U7, GST-U12, GST-U22, GST-U24, and GST-U25), were selected for further study. Quantitative PCR analysis verified the TNTresponsive up-regulation, with GST-U24 (At1g17180) and GST-U25 (At1g17170) the most up-regulated (252-and 177-fold, respectively; Fig.…”

Section: Up-regulation Of Gsts In Response To Tntmentioning

confidence: 99%

“…Plants engineered to express bacterial nitroreductases, which also perform this transformation step, have increased TNT transformation activity and show dramatically enhanced resistance to TNT (Hannink et al, 2001;Rylott et al, 2011a). The additional functionality of HADNTs and ADNTs permits their subsequent conjugation to amino acids, organic acids, and sugars (Bhadra et al, 1999(Bhadra et al, , 2001, and conjugation of HADNT and ADNT isomers to Glc by Arabidopsis glucosyltransferases has been characterized (Gandia-Herrero et al, 2008), with research suggesting that these conjugates are subsequently sequestered within the cell walls .…”

mentioning

confidence: 99%

“…Since GSTs have evolved the ability to catalyze glutathionelinked reactions with thousands of different chemical structures, it has been hypothesized that GSTs should play a central role, alongside glucosyltransferases, in the detoxification of TNT (Mezzari et al, 2005;Brentner et al, 2008). Gene expression studies in poplar (Tanaka et al, 2007;Brentner et al, 2008) and Arabidopsis (Ekman et al, 2003;Mezzari et al, 2005;Gandia-Herrero et al, 2008) have identified GSTs up-regulated in response to TNT; however, to date, the biochemical response of GSTs toward TNT has not been investigated. The overexpression of plant GSTs has been shown to increase resistance to a range of stresses, with some t class GSTs shown to detoxify herbicides via a conjugation activity (Dixon and Edwards, 2010;Cummins et al, 2011).…”

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confidence: 99%

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Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene

et al. 2014

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The explosive 2,4,6-trinitrotoluene (TNT) is a major worldwide military pollutant. The presence of this toxic and highly persistent pollutant, particularly at military sites and former manufacturing facilities, presents various health and environmental concerns. Due to the chemically resistant structure of TNT, it has proven to be highly recalcitrant to biodegradation in the environment. Here, we demonstrate the importance of two glutathione transferases (GSTs), GST-U24 and GST-U25, from Arabidopsis (Arabidopsis thaliana) that are specifically up-regulated in response to TNT exposure. To assess the role of GST-U24 and GST-U25, we purified and characterized recombinant forms of both enzymes and demonstrated the formation of three TNT glutathionyl products. Importantly, GST-U25 catalyzed the denitration of TNT to form 2-glutathionyl-4,6-dinitrotoluene, a product that is likely to be more amenable to subsequent biodegradation in the environment. Despite the presence of this biochemical detoxification pathway in plants, physiological concentrations of GST-U24 and GST-U25 result in only a limited innate ability to cope with the levels of TNT found at contaminated sites. We demonstrate that Arabidopsis plants overexpressing GST-U24 and GST-U25 exhibit significantly enhanced ability to withstand and detoxify TNT, properties that could be applied for in planta detoxification of TNT in the field. The overexpressing lines removed significantly more TNT from soil and exhibited a corresponding reduction in glutathione levels when compared with wild-type plants. However, in the absence of TNT, overexpression of these GSTs reduces root and shoot biomass, and although glutathione levels are not affected, this effect has implications for xenobiotic detoxification.The containment and cleanup of environmental pollutants is increasingly both a legal requirement and a responsible action in many developed countries. The most commonly used explosives in military weapons are 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and their continual use, along with production and decommissioning, are progressively contaminating millions of hectares of military land . Bioremediation of TNT is particularly challenging, as the electron-withdrawing properties of the three nitro groups render the aromatic ring particularly resistant to oxidative attack and ring cleavage by microbial oxygenases, which in the environment are normally central to the biodegradation of aromatic compounds (Qasim et al., 2007). In the United States, the Environmental Protection Agency and the military are addressing methods by which toxic TNT and RDX can be contained and detoxified on active military training ranges. One way this problem might be tackled is through the use of plants that are adapted to detoxify these compounds. This could be achieved either by traditional breeding programs or by genetic modification, as has been demonstrated previously for both RDX and TNT (Hannink et al., 2001;Rylott et al., 2006;Jackson et al., 2007).In t...

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Section: Activity Of Recombinant Gstsmentioning

confidence: 71%

Section: Glutathione-tnt Productsmentioning

confidence: 99%

Section: Up-regulation Of Gsts In Response To Tntmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene

et al. 2014

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Probing the Catalytic Promiscuity of a Regio‐ and Stereospecific C‐Glycosyltransferase from Mangifera indica

Chen

Wang

et al. 2015

Angewandte Chemie

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The catalytic promiscuity of the novel benzophenone C-glycosyltransferase,M iCGT,w hich is involved in the biosynthesis of mangiferin from Mangifera indica, was explored. MiCGT exhibited ar obust capability to regio-and stereospecific C-glycosylation of 35 structurally diverse druglike scaffolds and simple phenolics with UDP-glucose,a nd also formed O-and N-glycosides.Moreover,MiCGT was able to generate C-xylosides with UDP-xylose.T he OGT-reversibility of MiCGT was also exploited to generate C-glucosides with simple sugar donor.T hree aryl-C-glycosides exhibited potent SGLT2 inhibitory activities with IC 50 values of 2.6 , 7.6 , and 7.6 10 À7 m,r espectively.T hese findings demonstrate for the first time the significant potential of an enzymatic approach to diversification through C-glycosidation of bioactive natural and unnatural products in drug discovery.

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Probing the Catalytic Promiscuity of a Regio‐ and Stereospecific C‐Glycosyltransferase from Mangifera indica

et al. 2015

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The catalytic promiscuity of the novel benzophenone C-glycosyltransferase, MiCGT, which is involved in the biosynthesis of mangiferin from Mangifera indica, was explored. MiCGT exhibited a robust capability to regio- and stereospecific C-glycosylation of 35 structurally diverse druglike scaffolds and simple phenolics with UDP-glucose, and also formed O- and N-glycosides. Moreover, MiCGT was able to generate C-xylosides with UDP-xylose. The OGT-reversibility of MiCGT was also exploited to generate C-glucosides with simple sugar donor. Three aryl-C-glycosides exhibited potent SGLT2 inhibitory activities with IC50 values of 2.6×, 7.6×, and 7.6×10(-7) M, respectively. These findings demonstrate for the first time the significant potential of an enzymatic approach to diversification through C-glycosidation of bioactive natural and unnatural products in drug discovery.

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Detoxification of the explosive 2,4,6‐trinitrotoluene in Arabidopsis: discovery of bifunctional O‐ and C‐glucosyltransferases

Cited by 137 publications

References 37 publications

Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene

Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene

Probing the Catalytic Promiscuity of a Regio‐ and Stereospecific C‐Glycosyltransferase from Mangifera indica

Probing the Catalytic Promiscuity of a Regio‐ and Stereospecific C‐Glycosyltransferase from Mangifera indica

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