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)

The efficacy of the ethanol-inducible alc transgene expression system, derived from the filamentous fungus Aspergillus nidulans, has been demonstrated in transgenic tomato. Two direct comparisons have been made. First, this study has utilized two transgenic lines carrying distinct reporter genes (chloramphenicol acetyltransferase and beta-glucuronidase) to distinguish aspects of induction determined by the nature of the gene/gene product rather than that of the plant. Second, comparisons have been made to data generated in other species in order to identify any species-specific effects. The induction profiles for different genes in different species have shown remarkable similarity indicating the broad applicability of this gene switch. While there are minor differences observed between species, these probably arise from diversity in their metabolism. A series of potential alternative inducers have also been tested, revealing that ethanol (through metabolism to acetaldehyde) is better than other alcohols and ketones included in this study. Expression driven by alc was demonstrated to vary spatially, the upper younger leaves having higher activity than the lower older leaves; this will be important for some applications, and for experimental design. The highest levels of activity from ethanol-inducible transgene expression were determined to be the equivalent of those from the constitutive Cauliflower Mosaic Virus 35S promoter. This suggests that the alc system could be an important tool for plant functional genomics.
J Exp Bot 2005 Jun
PMID:Characterization of the ethanol-inducible alc gene expression system in tomato. 1585 14

The Arabidopsis thaliana THI1 protein is involved in thiamine biosynthesis and is targeted to both chloroplasts and mitochondria by N-terminal control regions. To investigate thi1 expression, a series of thi1 promoter deletions were fused to the beta-glucuronidase (GUS) reporter gene. Transgenic plants were generated and expression patterns obtained under different environmental conditions. The results show that expression derived from the thi1 promoter is detected early on during development and continues throughout the plant's life cycle. High levels of GUS expression are observed in both shoots and roots during vegetative growth although, in roots, expression is restricted to the vascular system. Deletion analysis of the thi1 promoter region identified a region that is responsive to light. The smallest fragment (designated Pthi322) encompasses 306 bp and possesses all the essential signals for tissue specificity, as well as responsiveness to stress conditions such as sugar deprivation, high salinity, and hypoxia.
J Exp Bot 2005 Jul
PMID:Functional characterization of the thi1 promoter region from Arabidopsis thaliana. 1589 30

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.
J Exp Bot 2005 Sep
PMID:A versatile promoter for the expression of proteins in glandular and non-glandular trichomes from a variety of plants. 1601 63

Arabidopsis plants possess a family of nine AtAtg8 gene homologues of the yeast autophagy-associated Apg8/Aut7 gene. To gain insight into how these genes function in plants, first, the expression patterns of five AtAtg8 homologues were analysed in young Arabidopsis plants grown under favourable growth conditions or following exposure to prolonged darkness or sugar starvation. Promoters, plus the entire coding regions (exons and introns) of the AtAtg8 genes, were fused to the beta-glucuronidase reporter gene and transformed into Arabidopsis plants. In all plants, grown under favourable growth conditions, beta-glucuronidase staining was much more significant in roots than in shoots. Different genes showed distinct spatial and temporal expression patterns in roots. In some transgenic plants, beta-glucuronidase staining in leaves was induced by prolonged darkness or sugar starvation. Next, Arabidopsis plants were transformed with chimeric gene-encoding Atg8f protein fused to N-terminal green fluorescent protein and C-terminal haemagglutinin epitope tags. Analysis of these plants showed that, under favourable growth conditions, the Atg8f protein is efficiently processed and is localized to autophagosome-resembling structures, both in the cytosol and in the central vacuole, in a similar manner to its processing and localization under starvation stresses. Moreover, treatment with a cocktail of proteasome inhibitors did not prevent the turnover of this protein, implying that its turnover takes place in the vacuoles, as occurs in yeasts. The results suggest that, in plants, the cellular processes involving the Atg8 genes function efficiently in young, non-senescing tissues, both under favourable growth conditions and under starvation stresses.
J Exp Bot 2005 Nov
PMID:The autophagy-associated Atg8 gene family operates both under favourable growth conditions and under starvation stresses in Arabidopsis plants. 1615 55

Ribonuclease LX (RNaseLX) from tomato (Solanum lycopersicum L.) belongs to the RNase T2/S-RNase superfamily of plant endoribonucleases and this is a report on the characterization of the RNaseLX gene and its encoded protein as a member of the phosphate starvation response in tomato. RNaseLX gene sequences were cloned by a PCR-assisted approach. RNaseLX promoter sequences contained the conserved binding motif of the transcription factor PHR1 known to mediate phosphate starvation-dependent gene expression. The increase of RNaseLX transcript levels in roots during phosphate starvation correlated with high promoter activity in transgenic plants carrying a PromLX::uidA gene construct and pointed to transcriptional control of RNaseLX expression. Histochemical staining for beta-glucuronidase activity and immunodetection of RNaseLX protein revealed striking RNaseLX expression in main and lateral root tips of phosphate-starved transgenic plants, specifically in epidermal cells, as well as in lateral and adventitious root primordia. Induced RNaseLX expression in roots correlated with stimulated growth and elongation of primary and lateral roots during phosphate deprivation. Phosphate-starvation-induced RNaseLX transcript levels in roots were not modulated by auxin or ethylene. These data indicate that the role of intracellular RNaseLX in the phosphate starvation response is connected with specific RNA turnover processes at the root tip.
J Exp Bot 2006
PMID:Tissue-specific expression of tomato Ribonuclease LX during phosphate starvation-induced root growth. 1699 Mar 75

Extracellular invertases are suggested to play a crucial role in the arbuscular mycorrhiza (AM) symbiosis to fulfil the increased sink function of the mycorrhizal root and the supply of the obligate biotrophic AM fungus with hexoses. In tomato (Lycopersicon esculentum), LIN6 represents an apoplastic invertase which is described as a key enzyme in establishing and maintaining sink metabolism. In this study, transcript levels of LIN6 were analysed in tomato roots colonized with the AM fungus Glomus intraradices. Using real-time RT-PCR, a nearly 3-fold increase in LIN6 mRNA levels was detected at late stages of mycorrhization (11 weeks after inoculation). A 1.8-fold induction could already be achieved at earlier stages (5 weeks after inoculation) using higher inoculum concentrations, whereas wounding of non-mycorrhizal roots resulted in up to 12-fold enhanced LIN6 transcripts. As revealed by in situ hybridization, the expression of LIN6 upon mycorrhization was specifically restricted to colonized cells and to the central cylinder. Such a strongly localized pattern due to mycorrhizal cells and to the central core could also be shown for promoter activity using transgenic Nicotiana tabacum plants expressing the gene coding for beta-glucuronidase under the control of the LIN6 promoter. The moderate induction of LIN6 expression in mycorrhizal tomato roots compared with stress-stimulated induction suggested a fine-tuning in the activation of sink metabolism in the mutualistic interaction, avoiding stress-induced defence reactions.
J Exp Bot 2006
PMID:Arbuscular mycorrhiza induces gene expression of the apoplastic invertase LIN6 in tomato (Lycopersicon esculentum) roots. 1705 Jun 39

A new type of protein was found in Arabidopsis thaliana, PCaP1, which is rich in glutamate and lysine residues. The protein bound (45)Ca(2+) even in the presence of a high concentration of Mg(2+). Real-time polymerase chain reaction and histochemical analysis of promoter-beta-glucuronidase fusions revealed that PCaP1 was expressed in most organs. The PCaP1 protein was detected immunochemically in these organs. Treatment of Arabidopsis seedlings with Cu(2+), sorbitol, or flagellin oligopeptide enhanced the transcription. On the other hand, other sugars, abscisic acid, gibberellic acid, dehydration, and low temperature had little or no effect on PCaP1 transcript abundance. The transient expression of PCaP1 fused to green fluorescent protein in Arabidopsis cells and the subcellular fractionation of tissue homogenate showed that PCaP1 protein is localized to the plasma membrane, although PCaP1 has no predicted transmembrane domain. PCaP1 was associated with the plasma membrane under natural conditions and was released from the membrane at high concentrations of Ca(2+) or Mg(2+) in vitro. These results suggest that the hydrophilic protein PCaP1 binds Ca(2+) and other cations and is stably associated with the plasma membrane.
J Exp Bot 2007
PMID:Molecular properties of a novel, hydrophilic cation-binding protein associated with the plasma membrane. 1726 65

The roles of the rice sucrose transporter, OsSUT1, have previously been examined in filling grain, germination, and early seedling growth. In the current work, the role that OsSUT1 plays in the transport of assimilate along the entire long-distance pathway, from the flag leaf blade to the base of the filling grain, was investigated. OsSUT1 promoter::GUS (beta-glucuronidase) reporter gene analysis and immunolocalization revealed that both OsSUT1 promoter::GUS activity and OsSUT protein were present in the mature phloem of all the vegetative tissues involved in the long-distance assimilate transport pathway during grain filling. In addition, expression was observed in the flag leaf blade and sheath prior to heading. The OsSUT1 promoter::GUS activity appeared to be largely confined to the companion cells within the phloem, whereas the protein localized to both the sieve tubes and the companion cells. RT-PCR analysis confirmed that the OsSUT1 transcript is expressed in the uppermost internode of the rice plant (internode-1). These OsSUT localization data were related to measurements of starch and soluble sugar content of these tissues, and localization of the carbohydrate reserves stored in the stem. Results from dye feeding experiments, to examine cellular connections, revealed a symplastic continuity between the phloem and surrounding parenchyma in the flag leaf blade, sheath, and internode-1 tissues. It is proposed that OsSUT1 may primarily play a role in phloem loading of sucrose retrieved from the apoplasm along the transport pathway.
J Exp Bot 2007
PMID:Involvement of the sucrose transporter, OsSUT1, in the long-distance pathway for assimilate transport in rice. 1772 97

A gene encoding a RING zinc finger ankyrin repeat protein (MjXB3), a putative E3 ubiquitin ligase, is highly expressed in petals of senescing four o'clock (Mirabilis jalapa) flowers, increasing >40,000-fold during the onset of visible senescence. The gene has homologues in many other species, and the Petunia homologue is strongly up-regulated in senescing Petunia corollas. Silencing the expression of this gene in Petunia, using virus-induced gene silencing, resulted in a 2 d extension in flower life. In Mirabilis, a 2 kb promoter region, 5' upstream of the MjXB3 gene, was isolated. The promoter sequence included putative binding sites for many DNA-binding proteins, including the bZIP, Myb, homeodomain-leucine zipper (HD-Zip), MADS-box, and WRKY transcription factors. The construct containing a 1 kb promoter region immediately upstream of the MjXB3 gene drove the strongest expression of the beta-glucuronidase (GUS) reporter gene in a transient expression assay. In Petunia, GUS expression under the control of this heterologous promoter fragment was specific to senescing flowers. The Mirabilis promoter GUS construct was tested in other flower species; while GUS activity in carnation petals was high during senescence, no expression was detected in three monocotyledonous flowers--daylily (Hemerocallis 'Stella d'Oro'), daffodil (Narcissus pseudonarcissus 'King Alfred'), and orchid (Dendrobium 'Emma White').
J Exp Bot 2007
PMID:Functional analysis of a RING domain ankyrin repeat protein that is highly expressed during flower senescence. 1805 40

The shortage of strong endosperm-specific expression promoters for driving the expression of recombinant protein genes in cereal endosperm is a major limitation in obtaining the required level and pattern of expression. Six promoters of seed storage glutelin genes (GluA-1, GluA-2, GluA-3, GluB-3, GluB-5, and GluC) were isolated from rice (Oryza sativa L.) genomic DNA by PCR. Their spatial and temporal expression patterns and expression potential in stable transgenic rice plants were examined with beta-glucuronidase (GUS) used as a reporter gene. All the promoters showed the expected spatial expression within the endosperm. The GluA-1, GluA-2, and GluA-3 promoters directed GUS expression mainly in the outer portion (peripheral region) of the endosperm. The GluB-5 and GluC promoters directed GUS expression in the whole endosperm, with the latter expressed almost evenly throughout the whole endosperm, a feature different from that of other rice glutelin gene promoters. The GluB-3 promoter directed GUS expression solely in aleurone and subaleurone layers. Promoter activities examined during seed maturation showed that the GluC promoter had much higher activity than the other promoters. These promoters are ideal candidates for achieving gene expression for multiple purposes in monocot endosperm but avoid promoter homology-based gene silencing. The GluC promoter did not contain the endosperm specificity-determining motifs GCN4, AACA, and the prolamin-box, which suggests the existence of additional regulatory mechanism in determining endosperm specificity.
J Exp Bot 2008
PMID:Expression pattern and activity of six glutelin gene promoters in transgenic rice. 1846 23


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