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)

A highly efficient and reproducible transformation system for rice ( Oryza sativa L. cv. Taipei 309) was developed using microprojectile bombardment of highly regenerative, green tissues. These tissues were induced from mature seeds on NB-based medium containing 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP) and high concentrations of cupric sulfate under dim light conditions; germinating shoots and roots were completely removed. Highly regenerative, green tissues were proliferated on the same medium and used as transformation targets. From 431 explants bombarded with transgenes [i.e. a hygromycin phosphotransferase ( hpt) gene plus one of a wheat thioredoxin h ( wtrxh), a barley NADP-thioredoxin reductase ( bntr), a maize Mutator transposable element ( mudrB) or beta-glucuronidase ( uidA; gus) gene], 28 independent transgenic events were obtained after an 8- to 12-week selection period, giving a 6.5% transformation frequency. Of the 28 independent events, 17 (61%) were regenerable. Co-transformation of the second introduced transgene was detected in 81% of the transgenic lines tested. Stable integration and expression of the foreign genes in T(0) plants and T(1) progeny were confirmed by DNA hybridization, western blot analyses and germination tests.
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PMID:Stable transformation of rice (Oryza sativa L.) via microprojectile bombardment of highly regenerative, green tissues derived from mature seed. 1455 31

DNA damage occurs as a by-product of intrinsic cellular processes, like DNA replication, or as a consequence of exposure to genotoxic agents. Organisms have evolved multiple mechanisms to avoid, tolerate, or repair DNA lesions. To gain insight into these processes, we have isolated mutants hypersensitive to DNA-damaging agents in the green alga Chlamydomonas reinhardtii. One mutant, Ble-1, showed decreased survival when it was treated with methyl methanesulfonate (MMS), bleomycin, or hydrogen peroxide (H2O2) but behaved like the wild type when it was exposed to UVC irradiation. Ble-1 carries an extensive chromosomal deletion that includes the gene encoding cytosolic thioredoxin h1 (Trxh1). Transformation of Ble-1 with a wild-type copy of Trxh1 fully corrected the MMS hypersensitivity and partly restored the tolerance to bleomycin. Trxh1 also complemented a defect in the repair of MMS-induced DNA strand breaks and alkali-labile sites. In addition, a Trxh1-beta-glucuronidase fusion protein translocated to the nucleus in response to treatment with MMS. However, somewhat surprisingly, Trxh1 failed to correct the Ble-1 hypersensitivity to H2O2. Moreover, Trxh1 suppression by RNA interference in a wild-type strain resulted in enhanced sensitivity to MMS and DNA repair defects but no increased cytotoxicity to H2O2. Thioredoxins have been implicated in oxidative-stress responses in many organisms. Yet our results indicate a specific role of Chlamydomonas Trxh1 in the repair of MMS-induced DNA damage, whereas it is dispensable for the response to H2O2. These observations also suggest functional specialization among cytosolic thioredoxins since another Chlamydomonas isoform (Trxh2) does not compensate for the lack of Trxh1.
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PMID:Functional specialization of Chlamydomonas reinhardtii cytosolic thioredoxin h1 in the response to alkylation-induced DNA damage. 1570 88

Sieve tubes are comprised of sieve elements, enucleated cells that are incapable of RNA and protein synthesis. The proteins in sieve elements are supplied from the neighboring companion cells through plasmodesmata. In rice plants, it was unclear whether or not all proteins produced in companion cells had the same distribution pattern in the sieve element-companion cell complex. In this study, the distribution pattern of four proteins, beta-glucuronidase (GUS), green fluorescent protein (GFP), thioredoxin h (TRXh) and glutathione S-transferase (GST) were analyzed. The foreign proteins GUS and GFP were expressed in transgenic rice plants under the control of the TRXh gene promoter (PTRXh), a companion cell-specific promoter. Analysis of leaf cross-sections of PTRXh-GUS and PTRXh-GFP plants indicated high accumulation of GUS and GFP, respectively, in companion cells rather than in sieve elements. GUS and GFP were also detected in phloem sap collected from leaf sheaths of the transgenic rice plants, suggesting these proteins could enter sieve elements. Relative amounts of GFP and endogenous phloem proteins, TRXh and GST, in phloem sap and total leaf extracts were compared. Compared to TRXh and GST, GFP content was higher in total leaf extracts, but lower in phloem sap, suggesting that GFP accumulated mainly in companion cells rather than in sieve elements. On the other hand, TRXh and GST appeared to accumulate in sieve elements rather than in companion cells. These results indicate the evidence for differential distribution of proteins between sieve elements and companion cells in rice plants.
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PMID:Differential distribution of proteins expressed in companion cells in the sieve element-companion cell complex of rice plants. 1612 Jun 85

Plant thioredoxins (TRXs) are involved in redox regulation of a wide variety processes and usually exhibit organ specificity. We report strong evidence that chloroplastic TRXs are localized in heterotrophic tissues and suggest some ways in which they might participate in several metabolic and developmental processes. The promoter regions of the chloroplastic f and m1 TRX genes were isolated from a pea (Pisum sativum) plant genomic bank. Histochemical staining for beta-glucuronidase (GUS) in transgenic homozygous Arabidopsis (Arabidopsis thaliana) plants showed preferential expression of the 444-bp PsTRXf1 promoter in early seedlings, stems, leaves, and roots, as well as in flowers, stigma, pollen grains, and filaments. GUS activity under the control of the 1,874-bp PsTRXm1 promoter was restricted to the leaves, roots, seeds, and flowers. To gain insight into the translational regulation of these genes, a series of deletions of 5' elements in both TRX promoters were analyzed. The results revealed that a 126-bp construct of the PsTRXf2 promoter was unable to reproduce the expression pattern observed with the full promoter. The differences in expression and tissue specificity between PsTRXm1 and the deleted promoters PsTRXm2 and PsTRXm3 suggest the existence of upstream positive or negative regulatory regions that affect tissue specificity, sucrose metabolism, and light regulation. PsTRXm1 expression is finely regulated by light and possibly by other metabolic factors. In situ hybridization experiments confirmed new localizations of these chloroplastic TRX transcripts in vascular tissues and flowers, and therefore suggest possible new functions in heterotrophic tissues related to cell division, germination, and plant reproduction.
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PMID:Localization in roots and flowers of pea chloroplastic thioredoxin f and thioredoxin m proteins reveals new roles in nonphotosynthetic organs. 1788 84