Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.31 (beta-glucuronidase)
7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have observed pigmented cytoplasmic granules, with the characteristic staining properties of lipofuscin (ceroid, "wear-and-tear") pigment, in newborn human liver. The pigment is found at the periphery of the lobule in hepatocytes and some bile ductular cells. It is acid-fast, PAS-positive after diastase digestion, slightly argyophilic and sudanophilic, and markedly Schmorl's- and peroxidase positive in paraffin sections. Difficult to see in sections stained with hematoxylin and eosin, the pigment can be detected in unstained sections. The granules also resemble lipofuscin found in adult tissues, in their ultra-structural and enzymatic properties. They are polymorphic, contain granular material of moderate and high electron opacity, and are delimited by a single membrane. Acid phosphatase and beta-glucuronidase activities are visualized in the newborn granules, identifying them as lysosomes. The granules also contain copper and, to a much lesser extent, iron. The accumulation of lipofuscin pigment in lysosomes in many tissues correlates well with aging, and this process has been interpreted as a reflection of cellular degeneration or wear-and-tear. However, the presence of lipofuscin granules as a constant component of neonatal liver suggests that they are not a measure of cellular senescence.
...
PMID:Lipofuscin (aging) pigment granules of the newborn human liver. 418 73

The concentrations of protein and copper and the activities of acid and alkaline phosphatase and beta-glucuronidase were measured in the uterine fluid of 8 25-38 year old women using the copper-T (Cu-T) 200 device for intrauterine contraception. Specimens were obtained in the proliferative phase on Cycle Days 10-12 of 1 menstrual cycle, and in the secretory phase on Days 20-23 during the next cycle prior to the insertion of the Cu-T, and during the same cycle days in Cycles 2 or 3 or 6 or 7 following insertion. Uterine fluid was obtained by irrigating the uterine cavity with physiological saline, while endometrial biopsies were taken for histological dating of the endometrium. The protein concentration of the uterine washings did not change significantly as a result of the Cu-T insertion. There was a significant difference (p.001) in Cycles 2 or 3 and 6 or 7 following insertion. Acid phosphatase activity was not influenced by the presence of the device. The betaglucuronidase in the fluid obtained during the proliferative phase showed a significant increase (p .001) DURING THE TIME WHEN the device was situ. The device caused a significant increase in the copper concentration in both phases, while the copper level in the blood serum remained unchanged. There was as increased number of white blood cells in the washings obtained during the secretory phase. The increase in the copper concentration of the uterine fluid might be the cause of the Cu-T antifertility effect due to a spermatotoxic and/or blastotoxic effect, as may the enzymic changes and increase of white blood cells.
...
PMID:Intrauterine contraception with the copper-T device. 4. Influence on protein and copper concentrations and enzyme activities in uterine washings. 456 82

Mouse calvaria were maintained in organ culture without serum additives. The effects of Cu2+ on bone resorption and on the synthesis and action of prostaglandins were studied. Non-toxic concentrations of copper sulphate (5 microM) were found to decrease active resorption, measured by 45Ca release, to 54% control values (p less than 0.001), while prostaglandin F (PGF), prostaglandin E2 (PGE2), and 6-keto-prostaglandin F1 alpha, (6-keto-PGF1 alpha), determined by radioimmunoassay, were increased above controls (p less than 0.05). These effects of Cu2+ on prostaglandin synthesis were confirmed by the isolation and quantitation of [3H]-labelled metabolites released from calvaria which had been pre-labelled with [3H]-arachidonic acid. PGE2, PGF2 alpha, 6-keto-PGF1 alpha, and thromboxane B2 (TxB2) were all higher in copper-exposed calvaria, but their relative amounts remained unchanged. There was no evidence that Cu2+ influenced the mobilisation of [3H]-arachidonic acid from prelabelled calvaria. The stimulation of bone resorption by exogenous prostaglandins was decreased in the presence of Cu2+ (p less than 0.005), while parathormone-mediated bone resorption was virtually unaffected. Cu2+ also increased the inhibition of bone resorption seen with indomethacin (p less than 0.05). In addition to the effects of the metal on prostaglandin action Cu2+ also decreased beta-glucuronidase activity in the media to 86% of the control values (p less than 0.001). The action of Cu2+ in inhibiting bone resorption in vitro appears complex but does not involve inhibition of prostaglandin synthesis. It is likely that Cu2+ has more than one inhibitory locus.
...
PMID:Inhibition of prostaglandin action and bone resorption by copper. 644 29

Iduronate sulfatase was purified from human liver for an investigation of the degradative pathway of dermatan sulfate. An overall 80-fold purification was achieved and, more importantly, the preparation was free of alpha-L-iduronidase, beta-glucuronidase, N-acetylgalactosamine 4-sulfate sulfatase (arylsulfatase B) and highly enriched in beta-N-acetylhexosaminidase. The liver enzyme appeared to be composed of several molecular species. The enzyme activity was optimal at pH 4.0 and its Km was 10--20 microM with sulfoiduronyl sulfoanhydromannitol. Chloride was inhibitory at high concentration and among divalent metal ions, only copper was inhibitory. Nitrocatechol sulfate was not a substrate, but did show competitive inhibition. Its Ki for iduronate sulfatase was similar to its Km for arylsulfatase, suggesting a similarity in the substrate binding sites of iduronate sulfatase and arylsulfatases.
...
PMID:Purification and some properties of human liver iduronate sulfatase. 695 Sep 34

Appressorium formation in germinating Colletotrichum gloeosporioides is induced by the surface wax of the host, the avocado fruit. To elucidate the mechanism by which differentiation of appressorium formation is induced, the fungal genes specifically activated by this host signal were sought. From a cDNA library of the transcripts present in appressorium-forming conidia, the clones representing nongerminating conidia were removed by hybridization with cDNAs synthesized from the nongerminating conidia. From this subtracted library, clones that hybridized with cDNA for transcripts from appressorium-forming conidia and not with cDNA for transcripts from germinating conidia were selected. Three such clones were isolated and sequenced. The genes for these three transcripts were also cloned and sequenced. Northern blot analysis showed that transcripts that hybridized with these three clones were expressed in the conidium only during the process of appressorium formation induced by avocado surface wax, and that these transcripts were not detectable when appressorium formation was prevented even in the presence of avocado wax. Nucleotide sequences of the clones revealed that one clone, cap3, contained an open reading frame (ORF) that would code for a 26-amino acid, cysteine-rich peptide with significant homology to Neurospora crassa copper metallothionein. Another clone, cap5, contained an ORF that would code for a 27-amino acid cysteine-rich peptide with less homology to metallothioneins. Cu2+ and Cd2+ also induced the expression of these genes at lower levels. The histochemical analysis of transformants containing the cap5 promoter fused to the beta-glucuronidase (GUS) gene showed that the cap5 gene promoter caused GUS expression exclusively during appressorium formation and most of the gus activity was in the appressorium. The cap22 clone contained an ORF coding for a 227-amino acid polypeptide of 22 kDa, which did not show significant homology to any known proteins. Recombinant CAP22 protein was produced using a pET-19b expression system in Escherichia coli, purified, and used to prepare rabbit antibodies. Western blot analysis of proteins from the appressorium-forming conidia revealed a major cross-reacting protein at 43 kDa and a minor band at 68 kDa, indicating that the potential glycosylation sites found in the primary translation product were probably glycosylated. Results of immunogold localization showed that CAP22 protein was located on the wall of the appressorium.
...
PMID:Isolation and characterization of genes expressed uniquely during appressorium formation by Colletotrichum gloeosporioides conidia induced by the host surface wax. 777 33

A family of genes, the so-called msr genes (multiple stimulus response), has recently been identified on the basis of sequence homology in various plant species. Members of this gene family are thought to be regulated by a number of environmental or developmental stimuli, although it is not known whether any one member responds more specifically to one stimulus, or whether each gene member responds to various environmental stimuli. In this report, we address this question by studying the tobacco msr gene str246C. Using transgenic tobacco plants containing 2.1 kb of 5' flanking DNA sequence from the str246C gene fused to the beta-glucuronidase (GUS) coding region, the complex expression pattern of the str246C promoter has been characterized. Expression of the str246C promoter is strongly and rapidly induced by bacterial, fungal and viral infection and this induction is systemic. Elicitor preparations from phytopathogenic bacteria and fungi activate the str246C promoter to high levels, as do wounding, the application of auxin, auxin and cytokinin, salicylic acid or copper sulfate, indicating the absence of gene specialization within the msr gene family, at least for str246C. In addition, GUS activity was visualized histochemically in root meristematic tissues of tobacco seedlings and is restricted to roots and sepals of mature plants. Finally, analysis of a series of 5' deletions of the str246C promoter-GUS gene fusion in transgenic tobacco plants confirms the involvement of multiple regulatory elements. A region of 83 bp was found to be necessary for induction of promoter activity in response to Pseudomonas solanacearum, while auxin inducibility and root expression are apparently not controlled by this element, since its removal does not abolish either response. An element of the promoter with a negative effect on promoter activation by P. solanacearum was also identified.
...
PMID:Developmental and pathogen-induced activation of an msr gene, str 246C, from tobacco involves multiple regulatory elements. 777 37

We determined the 5'-flanking sequences of two nuclear genes (SodCc1 and SodCc2) encoding cytosolic copper/zinc-superoxide dismutase in rice (Oryza sativa L.). Utilizing transient beta-glucuronidase (GUS) reporter assays, functional promoter-GUS analysis was performed in rice protoplasts exposed to the phytohormone abscisic acid (ABA) or the antioxidant sulfhydryl reagent, dithiothreitol (DTT). Transcriptional activities from both SodCc-GUS fusions were stimulated by DTT, which induces the promoter activity of the tobacco SodCc gene [Proc. Natl. Acad. Sci. USA 90 (1993) 3108-3112]. ABA had no effect on SodCcl-GUS expression but specifically induced the gene expression of the SodCc2-GUS fusion. The simultaneous application of ABA and gibberellin A3, however, abolished the enhancing effect of ABA. These results indicated that two rice SodCc promoters differentially respond to externally supplied ABA and that one of the regulatory factors for plant SodCc expression is ABA in addition to cellular redox-modulating antioxidants.
...
PMID:Structure and differential response to abscisic acid of two promoters for the cytosolic copper/zinc-superoxide dismutase genes, SodCc1 and SodCc2, in rice protoplasts. 782 31

The present study demonstrates for the first time that iron ions can induce lipid peroxidation in intact macrophages without causing cell death. Macrophage lipid peroxidation increases cell-mediated oxidation of LDL, enhances the release of interleukin 1 and inhibits the release of apolipoprotein E from the macrophages. When cultured macrophages were exposed to ferrous ions (50 microM FeSO4) for 4 h at 37 degrees C, cellular lipid peroxidation (measured by analyses of malondialdehyde (MDA), conjugated dienes (CD), and lipid peroxides (PD)) increased 2-4-fold in comparison with non-treated cells. This process was iron-dose dependent, reached its maximum after 4 h of incubation, and was accompanied by 68% and 53% reductions in the content of the cellular linoleic (18:2), and arachidonic acid (20:4), respectively, and by 29% and 36% reductions of cellular vitamin E and vitamin A, respectively. Cell viability (measured by trypan blue exclusion, by [3H]thymidine incorporation into DNA, by analysis of the release of lactate dehydrogenase (LDH) or [3H]adenine), and cell morphology (studied by scanning electron microscopy) were not significantly affected by the iron-induced oxidative stress. Manitol and dimethylthiourea (DMTU), but not catalase or superoxide dismutase (SOD), significantly inhibited iron-induced cellular lipid peroxide formation, suggesting that hydroxyl radical, but not superoxides or hydrogen peroxides, mediated the iron-induced cellular lipid peroxidation. Incubation of LDL (0.2 mg of protein/ml) with oxidized macrophages resulted in LDL lipids peroxidation, as evidenced by an 8-fold increase in the LDL associated MDA in comparison with LDL that was incubated under similar conditions with non-oxidized macrophages. Furthermore, oxidation of LDL by oxidized macrophages in the presence of copper ions (10 microM CuSO4) was 2-fold higher in comparison with oxidation of LDL by non-oxidized macrophages. The release of apolipoprotein E from oxidized macrophages decreased by 50%, whereas macrophage release of beta-glucuronidase and of interleukin-1 beta increased by 83% and by a factor of 6, respectively. This study demonstrates for the first time that iron ions induce oxidation of the cellular polyunsaturated fatty acids in intact macrophages and that this cellular lipid peroxidation can subsequently induce LDL oxidation.
...
PMID:Iron induces lipid peroxidation in cultured macrophages, increases their ability to oxidatively modify LDL, and affects their secretory properties. 784 Aug 15

Pulmonary clearance and toxicity of cupric oxide (CuO) dusts, which are probably formed in refining and smelting factories, were investigated. Groups of three rats received intratracheal (i.t.) instillation of CuO at a dose of 20 micrograms Cu/rat in time-course experiments (up to 7 days post-instillation). Other groups of three rats received i.t. instillation of CuO at doses of 2.5, 5, 10, 30, 50 and 100 micrograms Cu/rat and were killed at 2 days post-instillation in dose-effect experiments. Intratracheally instilled CuO particles were cleared from the lung with a half-time of 37 h. Copper binding metallothionein (MT) was induced in a dose-dependent manner and detected at 12 h to 3 days post-instillation. Rapid clearance of CuO from the lung and induction of MT at 12 h post-instillation suggest that CuO particles were solubilized and then cleared from the lung. The acute pulmonary toxicity of CuO was evaluated by cytological (numbers of macrophages and polymorphonuclear leukocytes), biochemical and elemental inflammatory indices (lactate dehydrogenase and beta-glucuronidase activities and protein, sulfur, phosphorus and calcium contents) in the bronchoalveolar lavage (BAL) fluid. These inflammatory indices peaked at 12 h to 3 days post-instillation, and increased with dose over the dose range, except for phosphorus content. Dose-effect relationships in BAL inflammatory indicators of CuO-injected (i.t.) groups were compared to those of CuSO4-injected (i.t.) groups. The results of the comparison indicated that there was no significant difference in acute inflammatory potency between CuSO4 (soluble form of Cu) and CuO (insoluble form of Cu) in the rat lung.
...
PMID:Pulmonary clearance and toxicity of intratracheally instilled cupric oxide in rats. 836 41

Superoxide dismutases (SODs; superoxide: superoxide oxidoreductase, EC 1.15.1.1) play a key role in protection against oxygen radicals, and SOD gene expression is highly induced during environmental stress. To determine the conditions of SOD induction, the promoter of the cytosolic copper/zinc SOD (Cu/ZnSODcyt) gene was isolated in Nicotiana plumbaginifolia and fused to the beta-glucuronidase reporter gene. Oxidative stress is likely to alter the cellular redox in favor of the oxidized status. Surprisingly, the expression of the Cu/ZnSODcyt gene is induced by sulfhydryl antioxidants such as reduced glutathione, cysteine, and dithiothreitol, whereas the oxidized forms of glutathione and cysteine have no effect. It is therefore possible that reduced glutathione directly acts as an antioxidant and simultaneously activates the Cu/ZnSODcyt gene during oxidative stress.
...
PMID:Redox-activated expression of the cytosolic copper/zinc superoxide dismutase gene in Nicotiana. 846 30


<< Previous 1 2 3 4 Next >>

---