Uridine diphosphate(UDP)-glycosyltransferases(UGTS)are widely distributed within living organisms and share roles in biotransformation of various lipophilic endo-and xenobiotics with activated UDP sugars.In this study...Uridine diphosphate(UDP)-glycosyltransferases(UGTS)are widely distributed within living organisms and share roles in biotransformation of various lipophilic endo-and xenobiotics with activated UDP sugars.In this study,it was found that the activity of UGTs in abamectin-resistant(AbR)strain was significantly higher(2.3-fod)than that in susceptible strain(SS)of Tetramychus cinnabarinus.Further analysis showed that 5-nitrouracil,the inhibitor ofUGTs,could enhance the lethal effect of abamectin on mites.From the previous microarray results,we found an UGT gene(UGT201D3)overexpressed in AbR strain.Quantitative PCR analysis showed that UGT20ID3 was highly expressed and more inducible with abamectin exposure in the AbR strain.After silencing the tran-scription of UGT201D3,the activity of UGTs was decreased and the susceptibility to abamectin was increased in AbR strain whereas it was not in sS.Furthermore,UGT201D3 gene was then succefully expressed in Escherichia coli.The recombinant UGT20ID3 exhibited a-naphthol activity(2.810.43 nmol mg protein/min),and the enzyme activity could be inhibited by abamectin(inhibitory concentration at 50%:57.50±3.54 μmol/L).High-performance liquid chromatography analysis demonstrated that the recombinant UGT201D3 could efctively deplete abamectin(15.77%±3.72%)incubating with 150 ug protein for 6 h.These results provided direct evidence that UGT201D3 was involved in abamectin resistance in T cinnabarinus.展开更多
Homocysteine(Hcy)is a sulfur-containing amino acid derived from the essential amino acid methionine(Met).Circulating levels of Hcy in animals can be increased by feeding on Met-enriched diets,which is generally consid...Homocysteine(Hcy)is a sulfur-containing amino acid derived from the essential amino acid methionine(Met).Circulating levels of Hcy in animals can be increased by feeding on Met-enriched diets,which is generally considered harmful.Spiders are one of the largest groups of obligate carnivores and feed on animals high in protein and Met.We analyzed the Hcy metabolism pathways in 18 species of 3 taxa(Mammalia,Insecta,and Arachnida)and found that the betaine-dependent remethylation pathway(BRP)was present in all carnivorous arachnid species and mammals but absent in insects and red spider mites.We then studied the Hcy metabolism pathway in Pardosa pseudoannulata.In P.pseudoannulata,Hcy is metabolized through the transsulfuration pathway,BRP,and S-methylmethionine-dependent remethylation pathway.Because of a prior duplication event of the betaine homocysteine S-methyltransferase(BHMT)gene in the BRP,BHMTa and BHMTb are present in tandem in the genome of P.pseudoannulata.The high expression levels of BHMTa and its high abundance in detoxification tissues indicate that it plays an important role in the BRP;the ability of BHMTa and BHMTb to remethylate Hcy using betaine as substrate was similar.Compared with other Hcy metabolic enzyme genes,BHMT responded quickly to the application of Hcy or betaine.In sum,the BRP is important in Hcy metabolism in P.pseudoannulata and in other spider species.展开更多
基金by Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2017jcyjBX0061)the National Natural Science Foundation of China(31672085).
文摘Uridine diphosphate(UDP)-glycosyltransferases(UGTS)are widely distributed within living organisms and share roles in biotransformation of various lipophilic endo-and xenobiotics with activated UDP sugars.In this study,it was found that the activity of UGTs in abamectin-resistant(AbR)strain was significantly higher(2.3-fod)than that in susceptible strain(SS)of Tetramychus cinnabarinus.Further analysis showed that 5-nitrouracil,the inhibitor ofUGTs,could enhance the lethal effect of abamectin on mites.From the previous microarray results,we found an UGT gene(UGT201D3)overexpressed in AbR strain.Quantitative PCR analysis showed that UGT20ID3 was highly expressed and more inducible with abamectin exposure in the AbR strain.After silencing the tran-scription of UGT201D3,the activity of UGTs was decreased and the susceptibility to abamectin was increased in AbR strain whereas it was not in sS.Furthermore,UGT201D3 gene was then succefully expressed in Escherichia coli.The recombinant UGT20ID3 exhibited a-naphthol activity(2.810.43 nmol mg protein/min),and the enzyme activity could be inhibited by abamectin(inhibitory concentration at 50%:57.50±3.54 μmol/L).High-performance liquid chromatography analysis demonstrated that the recombinant UGT201D3 could efctively deplete abamectin(15.77%±3.72%)incubating with 150 ug protein for 6 h.These results provided direct evidence that UGT201D3 was involved in abamectin resistance in T cinnabarinus.
基金This work was supported by the National Nature Sci-ence China Foundation(grant number 31772185 and 31972296).
文摘Homocysteine(Hcy)is a sulfur-containing amino acid derived from the essential amino acid methionine(Met).Circulating levels of Hcy in animals can be increased by feeding on Met-enriched diets,which is generally considered harmful.Spiders are one of the largest groups of obligate carnivores and feed on animals high in protein and Met.We analyzed the Hcy metabolism pathways in 18 species of 3 taxa(Mammalia,Insecta,and Arachnida)and found that the betaine-dependent remethylation pathway(BRP)was present in all carnivorous arachnid species and mammals but absent in insects and red spider mites.We then studied the Hcy metabolism pathway in Pardosa pseudoannulata.In P.pseudoannulata,Hcy is metabolized through the transsulfuration pathway,BRP,and S-methylmethionine-dependent remethylation pathway.Because of a prior duplication event of the betaine homocysteine S-methyltransferase(BHMT)gene in the BRP,BHMTa and BHMTb are present in tandem in the genome of P.pseudoannulata.The high expression levels of BHMTa and its high abundance in detoxification tissues indicate that it plays an important role in the BRP;the ability of BHMTa and BHMTb to remethylate Hcy using betaine as substrate was similar.Compared with other Hcy metabolic enzyme genes,BHMT responded quickly to the application of Hcy or betaine.In sum,the BRP is important in Hcy metabolism in P.pseudoannulata and in other spider species.
