Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To analyze the promoter region(s) of divergently transcribed fungal genes, a twin-reporter vector was constructed. This vector contains two divergently oriented reported genes, encoding Escherichia coli beta-glucuronidase (uidA) and E. coli beta-galactosidase (lacZ). Terminator regions of the Aspergillus nidulans nitrate and nitrite reductase-encoding genes, niaD and niiA, respectively, have been cloned 3' to the reporter genes to ensure proficient transcription termination of the reporter genes. The reporter genes have been separated by a unique NotI restriction site, which can be used for the insertion of expression signals. A mutant argB selection marker has been introduced in order to obtain A. nidulans transformants with a single copy of the vector integrated at the argB locus. The use of the vector was demonstrated by insertion of the A. nidulans niaD-niiA intergenic region and analysis of A. nidulans transformants obtained with this construct. Control of expression of both reporter genes was found to be in accordance with previously published data on control of nitrate assimilation [Cove, Biol. Rev. 54 (1979) 291-327].
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PMID:A twin-reporter vector for simultaneous analysis of expression signals of divergently transcribed, contiguous genes in filamentous fungi. 191 71

A fibre-free diet, or the same diet supplemented with 100 g cabbage or carrot cell-wall preparation/kg, was fed to rats for 28 days and the activities of a number of caecal microbial enzymes (azoreductase, aryl nitroreductase, beta-glucosidase, beta-glucuronidase, imidazole nitroreductase and nitrite reductase) were determined in vitro. The plant cell-wall preparations diluted the gut contents and decreased the number of bacteria per gram of caecal contents. Enzyme activities per gram of caecal contents were also decreased, with the exception of beta-glucosidase activity which was significantly increased. These plant cell-wall preparations also increased caecal size, and thereby significantly increased total activity per caecum of microbial azoreductase, aryl nitroreductase, beta-glucosidase and beta-glucuronidase. When bacterial metabolism was expressed per 10(9) bacteria, all enzyme activities were significantly increased in caecal samples from rats fed the plant cell-wall preparations. There was an overall concordance of 0.91 between all the enzymes when expressed per 10(9) bacteria, but of only 0.38 when enzyme activities were expressed per gram of caecal contents.
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PMID:Metabolic profile of caecal micro-organisms from rats fed indigestible plant cell-wall components. 629 83

A structural gene encoding nitrite reductase (NiR) in bean (Phaseolus vulgaris) has been cloned and sequenced. The NiR gene is present as a single copy encoding a protein of 582 amino acids. The bean NiR protein is synthesized as a precursor with an amino-terminal transit peptide (TP) consisting of 18 amino acid residues. The bean NiR transit peptide shows similarity to the TPs of other known plant NiRs. The NiR gene is expressed in trifoliate leaves and in roots of 20-day old bean plants where transcript accumulation is nitrate-inducible. Gene expression occurs in a circadian rhythm and induced by light in leaves of dark-adapted plants. A particular 100 bp sequence is present in the promoter and in the first intron of the NiR gene. Several copies of this 100 bp sequence are present in the bean genome. Comparisons between the promoter of the bean NiR gene and of two bean nitrate reductase genes (NR1 and NR2) show a limited number of conserved motifs, although the genes are presumed to be co-regulated. Comparisons are also made between the bean NiR promoter and the spinach NiR promoter. Transformation of tobacco plants with the bean NiR promoter fused to the GUS reporter gene (beta-glucuronidase) shows that the bean NiR promoter is nitrate-regulated and that the presence of the 100 bp sequence influences the level of GUS activity. NiR-coding sequences are not required for nitrate regulation but have a quantitative effect on the measured GUS activity.
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PMID:Structure and expression of a nitrite reductase gene from bean (Phaseolus vulgaris) and promoter analysis in transgenic tobacco. 786 86

Nitrate (NR) and nitrite reductase (NiR) catalyse the reduction of nitrate to ammonium. The regulation of NR and NiR gene expression by carbohydrates (C) and nitrogen (N) metabolites was studied using detached leaves. In the dark, glucose fructose and sucrose supplied to detached green leaves of dark-adapted Nicotiana plumbaginifolia plants resulted in NR mRNA and protein accumulation and the loss of circadian rhythmicity in the size of the transcript pool. The characterization of transgenic plants expressing either a NR cDNA controlled by the 35S CaMV promoter or a transcriptional fusion between the tobacco nia1 (NR structural gene) promoter and the beta-glucuronidase reporter gene, led us to conclude that C metabolite control is taking place at the transcriptional level. Under low light conditions (limiting photosynthetic conditions), the supply of glutamine or glutamate resulted in a drop in the level of NR mRNA. Exogenously supplied carbohydrates partially antagonized this inhibitory effect suggesting that the availability of N and C metabolites affects the expression of the NR gene. The effects of carbohydrates and glutamine on NiR expression were also studied. NiR mRNA levels in the dark were relatively insensitive to feeding with glucose. Glutamate and glutamine were less efficient at decreasing NiR mRNA than NR mRNA levels. In contrast to NR, NiR mRNA levels were significantly increased by light treatments, indicating that NiR display regulatory characteristics reminiscent of photosynthetic genes such as the small subunit of ribulose bisphosphate carboxylase than to NR.
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PMID:Regulation of nitrate and nitrite reductase expression in Nicotiana plumbaginifolia leaves by nitrogen and carbon metabolites. 822 Apr 46

Nitrate is an essential nitrogen source and serves as a signal to control growth and gene expression in plants. In rice, OsNAR2.1 is an essential partner of multiple OsNRT2 nitrate transporters for nitrate uptake over low and high concentration range. Previously, we have reported that -311 bp upstream fragment from the translational start site in the promoter of OsNAR2.1 gene is the nitrate responsive region. To identify the cis-acting DNA elements necessary for nitrate induced gene expression, we detected the expression of beta-glucuronidase (GUS) reporter in the transgenic rice driven by the OsNAR2.1 promoter with different lengths and site mutations of the 311 bp region. We found that -129 to -1 bp region is necessary for the nitrate-induced full activation of OsNAR2.1. Besides, the site mutations showed that the 20 bp fragment between -191 and -172 bp contains an enhancer binding site necessary to fully drive the OsNAR2.1 expression. Part of the 20 bp fragment is commonly presented in the sequences of different promoters of both the nitrate induced NAR2 genes and nitrite reductase NIR1 genes from various higher plants. These findings thus reveal the presence of conserved cis-acting element for mediating nitrate responses in plants.
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PMID:Two short sequences in OsNAR2.1 promoter are necessary for fully activating the nitrate induced gene expression in rice roots. 2615 Jan 7