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)

Granule-bound starch synthase is the key enzyme in amylose synthesis. The regulation of this gene was investigated using a chimaeric gene consisting of a 0.8 kb 5' upstream sequence of the granule-bound starch synthase gene from potato and the beta-glucuronidase gene which was introduced into potato using an Agrobacterium tumefaciens binary vector system. The chimaeric gene was highly expressed in stolons and tubers, whereas the expression in leaves, stems or roots from greenhouse-grown plants was relatively low. However, leaves from in vitro grown plantlets exhibited an elevated GUS expression. The expression of the chimaeric gene was inducible in leaves by growth on relatively high concentrations of sucrose, fructose and glucose and was about 30- to 50-fold higher than in leaves from greenhouse-grown plants. The granule-bound starch synthase gene is expressed organ-specifically since stolons and tubers showed GUS activities 125- to 3350-fold higher than in leaves. The activities in these two organs are 3- to 25-fold higher than the expression of the CaMV-GUS gene. Histochemical analysis of different tissues showed that only certain regions of leaves and roots express high GUS activities. Stolons and tubers show high expression.
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PMID:Expression of a chimaeric granule-bound starch synthase-GUS gene in transgenic potato plants. 191 93

The aim of the work described in this paper was to characterize the tubers of potato (Solanum tuberosum var. Prairie) plants that had been transformed with the Escherichia coli ADPglucose pyrophosphorylase (EC 2.7.7.27) gene, glgC-16, under the control of a patatin promoter. Over 30 lines of transformed plants with increased ADPglucose pyrophosphorylase activity were obtained. The tubers of six of these lines were compared with those of control plants expressing the gene for beta-glucuronidase. The average increase in pyrophosphorylase activity was 200%, and the highest was 400%. Western immunoblotting of tuber extracts showed that the amounts of glgC-16 protein were linearly related to the extractable activity of the ADPglucose pyrophosphorylase. Cell fractionation studies showed that the increased activity of the pyrophosphorylase in the glgC-16 tubers had a similar intracellular location, the amyloplast fraction, to that found in the control tubers. No pleiotropic changes in the maximum catalytic activities of the following enzymes could be detected in the glgC-16 tubers: sucrose synthase, fructokinase, UDPglucose pyrophosphorylase, phosphofructokinase, soluble starch synthase, starch branching enzyme, phosphoglucomutase and alkaline inorganic pyrophosphatase. The glgC-16 tubers are held to be suitable for the study of the role of ADPglucose pyrophosphorylase in the control of starch synthesis.
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PMID:Characterization of transgenic potato (Solanum tuberosum) tubers with increased ADPglucose pyrophosphorylase. 897 57