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)

Subcellular localization and regulation of the spinach (Spinacia oleracea) cysteine synthase (O-acetyl-L-serine[thiol]-lyase, EC 4.2.99.8) isoforms (CysA, CysB, and CysC) were determined in transgenic tobacco (Nicotiana tabacum) and in spinach cell cultures. The 5' regions of CysB and CysC encoding the chloroplastic (CysB-TP) and the putative mitochondrial (CysC-TP) transit peptide (TP) sequences were fused to a bacterial beta-glucuronidase gene (gus) and expressed in tobacco under the control of the cauliflower mosaic virus 35S promoter. Subcellular fractionation of transgenic tobacco showed transportation of beta-glucuronidase proteins to chloroplasts by CysB-TP and to mitochondria by CysC-TP, respectively, indicating that both presequences were sufficient to act specifically as chloroplastic and mitochondrial TPs in vivo. The mRNA expression patterns of CysA (cytoplasmic form), CysB, and CysC genes under nitrogen- and sulfur-starved conditions were characterized in spinach cell cultures. In sulfur-starved cells, only slight differences (approximately 1.2- to 1.5-fold) in the mRNA levels of CysA and CysB were observed during the short-term (0-24 h) cultivation periods compared with cells grown in Murashige-Skoog medium. However, under nitrogen and nitrogen/sulfur double-deficient stress conditions, mRNA levels of CysC increased up to 500% of the original level within 72 h.
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PMID:Subcellular localization of spinach cysteine synthase isoforms and regulation of their gene expression by nitrogen and sulfur. 881 26

Arabidopsis thaliana expresses four nitrilases, three of which (NIT1, NIT2 and NIT3) are able to convert indole-3-acetonitrile to indole-3-acetic acid (IAA), the plant growth hormone, while the isozyme NIT4 is a beta-cyano-l-alanine hydratase/nitrilase. NIT3 promoter activity is marginal in leaves or roots of vegetative plants and undetectable in bolting and flowering plants, but its level increases strongly when plants experience sulphur deprivation. No other nitrilase genes respond to sulphur supply/deficiency. Neither N- nor P-deprivation cause detectable changes in NIT3 promoter activity. In transgenic plants expressing uidA under the control of the NIT3 promoter (NIT3p::uidA), sulphate deprivation leads to the appearance of beta-glucuronidase activity in shoots and particularly in roots, most strongly in the conductive tissues and lateral root primordia. Deletion analysis allowed localization of the sulphur-responsive element to a 317 bp segment of the NIT3 promoter encompassing nt -2151 to -1834 upstream of the transcriptional start point. Both nitrilase polypeptide and nitrilase activity were also induced by sulphur starvation. NIT3 promoter activity was strongly induced by O-acetylserine, suggesting that, as is the case with enzymes of sulphate assimilation, sulphate deficiency may be communicated to NIT3 via an increase in the level of the cysteine precursor, O-acetylserine. During sulphur deprivation, a preferential depletion of the pool of the indole-3-acetonitrile precursor glucobrassicin compared with that of total glucosinolates was noticed. In the absence of an external sulphate supply, plants developed longer roots with a higher number of lateral roots. The increased growth of the root system occurred at the expense of shoot growth which was retarded under conditions of sulphur starvation. Taken together, these results suggest that a regulatory loop appears to exist by which sulphate deficiency, through an increase in glucobrassicin turnover and nitrilase 3 accumulation, initiates the production of extra auxin leading to increased root growth and branching, thus allowing the root system to penetrate new areas of soil effectively to gain access to fresh supplies of sulphur.
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PMID:A role for nitrilase 3 in the regulation of root morphology in sulphur-starving Arabidopsis thaliana. 1196 96

A DNA regulatory fragment was isolated from the promoter region of the OASA1 gene, encoding the cytosolic O-acetylserine(thiol)lyase enzyme that is highly expressed in Arabidopsis thaliana trichomes. This DNA fragment has been named an ATP fragment and comprises 1435 bp of the genomic region upstream of the OASA1 gene and 375 bp of the transcriptional initiation start site containing the first intron of the gene. The ATP fragment, fused to the green fluorescent protein (GFP) and beta-glucuronidase (GUS) reporter genes, is able to drive high-level gene expression in A. thaliana trichomes. Deletion analysis of the ATP fragment determined that the region from -266 to -66 contains regulatory elements required for trichome expression. In addition, the region from +112 to +375, comprising the first intronic region of the gene, is also essential for trichome gene expression. Expression of the full-length ATP fragment in tobacco and peppermint shows that this fragment is also able to drive expression in glandular trichomes and suggests additional biotechnological applications for this promoter.
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PMID:A versatile promoter for the expression of proteins in glandular and non-glandular trichomes from a variety of plants. 1601 63