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

To investigate the modifying role of intestinal microflora in the metabolism of chemical carcinogens in vivo, we subjected bile from Fischer rats treated per os with chemical carcinogens and related compounds to a mutagenicity assay in the presence and absence of a cell-free extract from human feces. A mixture of the bile sample and potassium phosphate buffer was incubated in the presence or absence of human cell-free fecal extract and then further incubated with a bacterial suspension of Salmonella typhimurium tester strains TA98 or TA100. Bile from rats treated with 1-nitropyrene (1-NP) produced about 2700 and 400 revertants per plate in strain TA98 in the presence and absence of the fecal extract, respectively. There was a drug dose- and bile volume-related response. Treatment of 1-NP-bile with beta-glucuronidase, but not aryl sulfatase, enhanced its mutagenicity. Cell-free extracts of some strains of intestinal bacteria (Bacteroides fragilis ATCC 12044, B. vulgatus ATCC 8482, B. thetaiotaomicron ATCC 12290, Bacteroides sp. strain 524, Eubacterium eligens VPI C15-48, Peptostreptococcus sp. strain 204 and Escherichia coli A-5-18) also enhanced the mutagenicity of 1-NP-bile. These bacterial cell-free extracts hydrolyzed the synthetic beta-D-glucuronides of phenolphthalein and/or p-nitrophenol. These data indicate that the glucuronide(s) of 1-NP-metabolite(s) secreted into bile can be hydrolyzed in the intestine by bacterial beta-glucuronidases to potent mutagenic aglycone(s).
 ...
PMID:Mutagenic activation of biliary metabolites of 1-nitropyrene by intestinal microflora. 398 38

Cassava ( Manihot esculenta Crantz) storage roots, organs accumulating large amounts of starch, develop from primary roots via secondary growth. The availability of promoters related to storage-root formation is a prerequisite for engineering root traits in cassava. Two cDNAs, c15 and c54, were identified from a storage-root cDNA library of cassava MCol1505 via differential screening. The transcripts of c15 and c54 were detected in storage roots but not in leaves by Northern analysis. Homology analysis of the deduced amino acid sequences showed that C15 is likely to be related to cytochrome P450 proteins, which are involved in the oxidative degradation of various compounds, while C54 may be related to Pt2L4, a cassava glutamic acid-rich protein. The promoter regions of c15 and c54 were isolated from the corresponding clones in a cassava genomic library. A 1,465-bp promoter fragment ( p15/1.5) of c15 and a 1,081-bp promoter region ( p54/1.0) of c54 were translationally fused to the uidA reporter gene, and introduced into cassava and Arabidopsis thaliana (L.) Heynh. The expression patterns of p15/1.5::uidA and p54/1.0::uidA in transgenic plants showed that both promoters are predominantly active in phloem, cambium and xylem vessels of vascular tissues from leaves, stems, and root systems. More importantly, strong beta-glucuronidase activity was also detected in the starch-rich parenchyma cells of transgenic storage roots. Our results demonstrate that the two promoters are related to vascular expression and secondary growth of storage roots in cassava.
 ...
PMID:Two cassava promoters related to vascular expression and storage root formation. 1368 Feb 28