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)

We investigated the 5'-upstream region of the gene encoding the catalytic subunit of the V-type H(+)-ATPase in Daucus carota. A genomic sublibrary was screened with a cDNA probe, and a 4-kilobase genomic clone was obtained covering the first two exons and about 3 kilobases of the 5'-upstream sequence. The intron/exon boundaries matched established consensus sequences. Within 240 base pairs (bp) upstream of the initiation codon three putative TATA boxes were found. Ribonuclease protection and primer extension analysis indicated that the three TATA boxes corresponded to two major and one minor transcription start sites. The flanking sequences of the two more proximal TATA boxes were nearly identical. Additional sequence motifs with putative regulatory function are two CCAAT boxes, an Sp1-binding consensus sequence, and long (TATA)n stretches within 800 bp of the 5'-upstream sequence. Transcriptional fusions to the beta-glucuronidase reporter gene were made for two different promoter constructs, and the resulting plasmids were mobilized into Agrobacterium tumefaciens. The analysis of beta-glucuronidase activities in the transformed carrot calli showed that 240 bp of the upstream sequence, including all three TATA boxes, led to low but detectable beta-glucuronidase expression; however, the larger construct, which included the putative Sp1-binding sequence and the (TATA)n stretches, led to an approximately 6-fold higher beta-glucuronidase expression. Histochemical analysis of beta-glucuronidase activity in the transformed calli showed no preferential expression in any specific cell type, in keeping with the presumed "housekeeping" character of the V-type H(+)-ATPase catalytic subunit gene.
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PMID:Structure and function of the promoter of the carrot V-type H(+)-ATPase catalytic subunit gene. 213 75

Genomic clones of human MANB gene encoding the lysosomal enzyme, alpha-mannosidase, have been isolated, sequenced and analyzed. The human MANB gene spans approximately 22 kb and consists of 24 exons. The 5' flanking region of the gene shows a high G+C content and has two Sp1 and three AP-2 sites. Promoter analysis using deletion constructs of the 5' flanking region fused to the bacterial CAT gene showed that 150 bp of 5' sequence could drive the expression of MANB in COS 7 cells. Determination of the sequence of the 5' end of the alpha-mannosidase mRNA by 5' RACE protocol showed that transcription is initiated from a cluster of sites centered -28 and -20 bp from the first in-frame ATG. These data demonstrate that, like other lysosomal enzyme genes such as those for beta-glucuronidase or beta-hexosaminidase, the human MANB gene is controlled by a short 5' flanking sequence located near the initiation codon.
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PMID:Characterization of the human MANB gene encoding lysosomal alpha-D-mannosidase. 937 Mar 1

Methylation of CpG islands spanning promoter regions is associated with control of gene expression, although it is unclear what mechanisms define the boundaries between methylated and unmethylated regions in the genome. Methylation of genomic DNA in mammals also affects the frequency of inherited diseases by predisposing them to CpG mutations. To gain insight into these issues, we investigated patterns of cytosine methylation on almost the entire beta-glucuronidase gene (GUSB) from normal leukocyte DNAs by bisulfite genomic sequencing. We mapped the boundaries of methylation that flank the 5'- and 3'-ends of the CpG island region, and correlated methylation status with transitional mutations at CpG sites. GenBank sequence analyses showed that the CpG island of human GUSB is juxtaposed with multiple Alu repeats and also includes multiple Sp1 sites upstream and downstream of the transcription start, which has been suggested to prevent CpG islands from becoming methylated. We show that cytosine methylation is extensive across the entire gene except for CpG sites in the proximal promoter region, exon 1, and part of intron 1; the unmethylated CpG island is embedded between densely methylated flanking regions containing multiple Alu repeats; a sharp boundary separates the methylated and unmethylated regions of the 5'-flank of the CpG island, but a gradual change in methylation density over 1.0 kb is observed in the 3'-flank of the CpG island; boundaries of the 5'-end and 3'-end of the CpG island contain multiple Sp1 sites in addition to Alu repeats; methylation in both strands is symmetrical except at the boundary regions between methylated and unmethylated regions; and nonmethylation of exon 1 correlates with the absence of transitional mutations at CpG sites in exon 1.
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PMID:Methylation patterns of the human beta-glucuronidase gene locus: boundaries of methylation and general implications for frequent point mutations at CpG dinucleotides. 1186 66

The building up of the cell wall is tightly dependent on the functionality of the secretory pathway. Syntaxins as well as other SNARE proteins play important roles during vesicle secretion and fusion. We have compared the secretion of newly synthesised cell-wall polysaccharides to that of secretory marker proteins such as secreted green-fluorescent protein (sec-GFP) and secreted rat preputial beta-glucuronidase (secRGUS) in leaf protoplasts and roots of wild-type and transgenic Nicotiana tabacum plants, overexpressing a syntaxin homologue NtSyr1 (Sp1) and its soluble variant Sp2 that interferes specifically with Sp1 function, affecting post-Golgi transport. In protoplasts transiently transformed with secGFP and Sp1, no variation was observed in the pattern of fluorescence with respect to control; on the contrary, GFP fluorescence accumulate within the cells in protoplasts co-transformed with secGFP and Sp2. Sp2 reduced the percentage of marker protein secretion to 53% as quantified with secRGUS. In protoplasts obtained from leaves of wild-type and transformed tobacco plants expressing Sp1, Sp2 and Sp1 plus Sp2, no remarkable differences in the percentage of newly synthesised polysaccharides incorporated into the regenerating cell walls were observed. The same results were confirmed in roots of whole transformed seedlings. Tests with cytochalasin D (CD) showed a marked decrease in the amount of newly synthesised polysaccharides into the wall and a simultaneous sharp increase in membrane-associated polysaccharides. SecRGUS secretion was also inhibited by CD. The data indicate that marker proteins and matrix polysaccharides, as well as cellulose synthase complexes, are secreted through the involvement of different secretory machineries.
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PMID:Secretion marker proteins and cell-wall polysaccharides move through different secretory pathways. 1703 71