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 ability of TPA to induce stable phenotypic changes that normally serve as markers of differentiation was examined in the four human non-T, non-B cell lines, NALL-1, NALM-16, REH and KM-3. In all four lines, noncytotoxic concentrations of the phorbol ester caused an extensive reduction in the number of cells expressing cALL surface antigen and terminal deoxynucleotidyl transferase. The disappearance of these markers correlated with the loss of cell proliferation. In one of the cell lines, NALL-1, TPA treatment gave rise to a significant increase in Ia-like antigen and antigen T-101, markers which represent more advanced stages of cell maturation. However, surface or cytoplasmic immunoglobins, indicators of mature B cells, were not detectable. Antigen 3A1, specific for myeloid and for T cells, antigen Leu-4, specific for T cells and antigen CM1, specific for monocytes, were also absent. In all cell lines, exposure to TPA resulted in an approximately two-fold increase in acid phosphatase and beta-glucuronidase activity. The emergence of these phenotype changes was not altered upon repeated washing of the TPA-treated cells. These results demonstrate that while TPA is capable of inducing various non-T, non-B cell lines to differentiate to a limited degree, differences exist between the lines in the extent to which they can mature towards the B-cell stage.
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PMID:Differentiation-associated changes in human non-T, non-B leukemia cell lines after treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). 671 62

1. Activities of dipeptidyl aminopeptidases (DAP), leucine arylamidase and beta-glucuronidase were assayed in red and white parts of mouse quandriceps femoris muscle 3 and 7 days after a single bout of prolonged running. 2. The activities of lysosomal acid hydrolases (DAP I, DAP II and beta-glucuronidase) were highly increased on the 3rd day after the exertion and then decreased by the 7th day. The response was more prominent in red than in white skeletal muscle. 3. The activities of two microsomal hydrolases, DAP IV and leucine arylamidase, increased much less than those of the lysosomal acid hydrolases. The highest activities were recorded on the 7th day after exertion. 4. The activity of DAP III, a cytoplasmic peptidase, was unaffected in red muscle but slightly increased in white muscle. 5. The protein content of red skeletal muscle, but not that of white muscle, decreased transiently after the running. 6. It seems that strenuous exercise selectively stimulates the lysosomal proteolytic system in skeletal muscle, while the others are less affected.
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PMID:Changes of dipeptidyl aminopeptidase activities in mouse skeletal muscle following prolonged running. 703 82

Amino acid analysis of oxidized or reduced and carboxymethylated beta-glucuronidase have shown the presence of 24 cysteic acid or S-carboxymethylcysteine residues respectively per mole of the tetrameric enzyme. Titration of sulfhydryl groups gave eight cysteine residues, and by difference 16 half-cystine residues per mole. Six peptides containing radiolabelled cysteine residues were isolated from pepsin and chymotrypsin digest of reduced and S-carboxymethylated beta-glucuronidase by ion-exchange chromatography or gel filtration, followed by paper ionophoresis and paper chromatography. The peptides were analysed for amino acids and sequenced by the dansyl-Edman procedure. Peptides containing cysteic acid were selectively recovered from thermolysin digests of performic acid-oxidized glucuronidase. The amino acid sequences confirmed that there were only six different peptide sequences containing either cysteine or half-cystine residues in the tetrameric enzyme, supporting the presence of four identical subunits. These sequences wer: (A)-Val-Asx-Val-Ile-Cys-Val-Asx-Ser-Tyr- (B)-Gly-Asx-Leu-Cys-Ser-Gly- (C)-Phe-Val-Val-Ile-Asx-Glx-Cys-Pro-Gly-Val-Gly- (D)-Val-Val-Cys-Leu- (E)-Gln-Ser-Gly-Cys-Leu-Val-Lys-Gly-Tyr- (F)-Cys-Asp-Arg-Tyr-Gly-Ile-Val-Val-.
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PMID:Amino acid sequences containing cysteine or half-cystine residues in beta-glucuronidase. 721 58

High mannose-type oligosaccharides of acid hydrolases are phosphorylated by the transfer of N-acetyl-glucosamine 1-phosphate to the 6 position of mannose. This is followed by removal of the covering N-acetyl-glucosamine residue to expose a phosphomonoester. We have examined the kinetics of this phosphorylation pathway in the murine macrophage line P388D1. Cells were labeled with [2-3H]mannose for 15-20 min and then chased with unlabeled mannose for various times up to 5 h. The lysosomal enzyme beta-glucuronidase was immunoprecipitated and its oligosaccharide units examined for extent of phosphorylation and uncovering. The first phosphorylated oligosaccharides were detected after 20 min of labeling. Most of the phosphorylation occurred during the first 40 min of the chase period, and a maximum of 30% of the oligosaccharide units were eventually phosphorylated. Oligosaccharides with one and two phosphodiesters were found. The earliest detectable phosphorylated species were devoid of the glucose residues known to be present on the lipid-linked oligosaccharide precursor. Uncovering of the phosphodiesters began shortly after the oligosaccharides were phosphorylated and occurred concomitantly with the removal of outer mannose residues. Taken together, these data demonstrate that phosphorylation of lysosomal enzyme oligosaccharides is a post-translational event. Proteolytic fragmentation of [3H]mannose-labeled beta-glucuronidase and partial digestion of [3H]leucine-labeled beta-glucuronidase with endo-beta-N-acetylglucosaminidase H suggest that there are 3 glycosylation sites per subunit. Each glycosylation site is partially phosphorylated. A portion of the high mannose oligosaccharides at one site are processed to complex-type units.
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PMID:The phosphorylation of beta-glucuronidase oligosaccharides in mouse P388D1 cells. 730 50

The turnover rate of an individual protein is a function of the rates of synthesis and loss of that protein. For most intracellular proteins, loss occurs through digestion by lysosomal or cytosolic proteases. Although a significant proportion of hepatic lysosomal enzymes is released from the hepatocyte by excretion into bile, the contribution of biliary excretion to the turnover of hepatic lysosomal enzymes has never been measured. Thus, we used in vivo pulse-labeling to determine the half-lives of two hepatic hydrolases, beta-galactosidase (beta-gal) and beta-glucuronidase (beta-glu). Each enzyme was purified by immunoisolation from hepatic lysosomes that were isolated at various times after injection of rats with 3H-labeled leucine. The decay curves for the specific radioactivities of beta-gal and beta-glu were used to calculate the half-lives of the proteins, which were 3.8 and 5.1 days, respectively. To determine the percent of total hepatic contents of each enzyme that was lost per day by biliary excretion, we collected bile from bile fistula rats for 24 hours and then used radioimmunoassays to quantitate the amounts of beta-gal and beta-glu in bile and liver samples of the same rats. We found that approximately 4% of the total hepatic contents of both beta-gal and beta-glu was excreted into bile per day. Finally, we used these data to calculate that 31% and 41% of hepatic losses of beta-gal and beta-glu, respectively, were due to biliary excretion. These results suggest that extracellular release through biliary excretion is a major mechanism contributing to the turnover of lysosomal hydrolases.
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PMID:Quantitative importance of biliary excretion to the turnover of hepatic lysosomal enzymes. 760 20

The purposes of this study are to develop an in vivo cell system that is suitable for the immunofluorescent detection of transiently expressed proteins targeted to plant peroxisomes and to determine whether a C-terminal serine-lysine-leucine (SKL) tripeptide, a consensus-targeting signal for mammalian peroxisomes, also targets proteins to plant peroxisomes. Protoplasts from mesophyll cells and from suspension-cultured cells initially were examined for their potential as an in vivo import system. Several were found suitable, but based on a combination of criteria, suspension-cultured tobacco (Nicotiana tabacum L. cv Bright Yellow 2) cells (TBY-2) were chosen. The tobacco cell extracts had catalase activity, and two polypeptides of approximately 55 and 57 kD specifically were detected on immunoblots with anti-cottonseed catalase immunoglobulins G as the probe. Indirect immunofluorescence microscopy with these immunoglobulins G revealed a punctate labeling pattern indicative of endogenous catalase localization within putative TBY-2 peroxisomes. The cells did not have to be completely converted to protoplasts for optimal microscopy; treatment with 0.1% (w/v) pectolyase for 2 h was sufficient. Microprojectile bombardment proved superior for transient transformation of the TBY-2 cells with plasmids encoding beta-glucuronidase, or chloramphenicol acetyltransferase (CAT), or CAT with an added C-terminal tripeptide (CAT-SKL). C-terminal SKL is a consensus, type 1, peroxisome targeting signal. Double indirect immunofluorescent labeling showed that CAT-SKL co-localized with endogenous catalase. Non-punctate, diffuse localization of CAT without SKL provided direct evidence that the C-terminal SKL tripeptide was necessary and sufficient for targeting of CAT to plant peroxisomes. These data demonstrate the effectiveness of this peroxisome targeting signal for plant cells.
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PMID:Development and application of an in vivo plant peroxisome import system. 777 May 24

Two beta-glucuronidase-deficient Mennonite siblings were found to be homozygous for a mutation in exon 3 of the beta-glucuronidase gene that produces a Leu-->Phe substitution (L176F). The siblings also have the previously described benign polymorphism, P649L. Although their cultured fibroblasts contained 1.5-2.2% of normal beta-glucuronidase activity, transient expression of the L176F/P649L cDNA in COS cells produced nearly as much enzyme activity as the wild-type control cDNA. The L176F/P649L enzyme was as stable as wild-type enzyme following endocytosis by fibroblasts and delivery to lysosomes, but was more labile to heat inactivation at 65 degrees C. To study the mutant enzyme at lower levels of expression, we stably transfected mouse mucopolysaccharidosis type VII cells with the L176F/P649L cDNA and selected single-copy cell lines. Metabolic labeling with [35S]methionine revealed that cell lines expressing the mutant enzyme activity at low levels (7-10% of the wild type) actually produced the same amount of enzyme protein as the cell lines expressing the more active wild-type enzyme. However, the cell lines expressing four times this much mutant enzyme protein produced 150-200% as much enzyme activity as the cell line expressing the single-copy wild-type cDNA. These data suggest that overexpression can drive the folding reaction or the self-association of mutant monomers to form active tetramers and, at least partially, correct the beta-glucuronidase deficiency seen at low levels of expression with certain missense mutations.
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PMID:Overexpression rescues the mutant phenotype of L176F mutation causing beta-glucuronidase deficiency mucopolysaccharidosis in two Mennonite siblings. 808 38

We studied the relationship between cell morphology and surface markers in three patients with granular lymphocyte proliferative disorders. In the two patients with CD3+ CD4-CD8+ cells, there were no atypical cells, and the granules were uniformly fine: In the third patient, who had CD3+ CD4+ CD8- cells, atypical nuclei and the irregular granules in in size were observed. The granules were stained with beta-glucuronidase showing localized coarse features and made clumps, in the staining pattern characteristic of granular lymphocytes. The patient with CD4- CD8+ cells showed cytotoxic T cell phenotype, and the other DN cells type (usually associated with a CD3+ CD4- CD8- phenotype). We obtained conflicting data about OK-NK and Leu 11 antibodies, which recognized CD16 antigen.
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PMID:[Cell morphology and surface markers in three patients with granular lymphocyte proliferative disorders of the T-cell type]. 810 90

Nodulin-24 is a nodule-specific protein of the peribacteroid membrane (PBM) in soybean. It has an apparent molecular mass of 33 kDa while its full-length cDNA encodes a polypeptide of only 24 kDa. In vitro transcription of nodulin-24 cDNA followed by translation resulted in a peptide translocated into microsomal membranes with cleavage of a signal sequence. The cleavage site of the signal sequence in nodulin-24 was determined to be between Ala (A25) and Arg (R26) by microsequencing of the [3H]leucine-labeled processed peptide. Fusion of the signal sequence of nodulin-24 with the beta-glucuronidase peptide prevented co-translational cleavage of the signal sequence although the translocation of the fused protein into microsomes occurred co-translationally. Trypsin treatment of membrane-translocated nodulin-24 did not result in any alteration in size suggesting that the newly synthesized peptide is fully protected in the membrane vesicle. Fusion of nodulin-24 with beta-glucuronidase also showed no change in size following trypsin treatment, suggesting that nodulin-24 has no membrane-spanning region. In addition, in vitro synthesized nodulin-24 was present in the supernatant fraction after sonication of microsomal membranes. Mature nodulin-24, on the other hand, is not solubilized from PBM by sodium carbonate (pH 11) or EGTA and is soluble only in detergent. These data suggest that nodulin-24 is synthesized as a lumenal protein in the endoplasmic reticulum and post-translationally attached to the membranes en route to the PBM. This processing results in a significant increase in the apparent molecular mass of nodulin-24 which may be due to the attachment of membrane lipids as this protein shares characteristics with membrane lipoproteins of many pathogenic bacteria.
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PMID:Nodulin-24 follows a novel pathway for integration into the peribacteroid membrane in soybean root nodules. 812 12

The NIa protein of plant potyviruses is a bifunctional protein containing an N-terminal VPg domain and a C-terminal proteinase region. The majority of tobacco etch potyvirus (TEV) NIa molecules are localized to the nucleus of infected cells, although a proportion of NIa is attached covalently as VPg to viral RNA in the cytoplasm. A suboptimal cleavage site that is recognized by the NIa proteinase is located between the two domains. This site was found to be utilized in the VPg-associated, but not the nuclear, pool of NIa. A mutation converting Glu-189 to Leu at the P1 position of the processing site inhibited internal cleavage. Introduction of this mutation into TEV-GUS, an engineered variant of TEV that expresses a reporter protein (beta-glucuronidase [GUS]) fused to the N terminus of the helper component-proteinase (HC-Pro), rendered the virus replication defective in tobacco protoplasts. Site-specific reversion of the mutant internal processing site to the wild-type sequence restored virus viability. In addition, the trans-processing activity of NIa proteinase was tested in vivo after introduction of an artificial cleavage site between the GUS and HC-Pro sequences in the cytoplasmic GUS/HC-Pro polyprotein encoded by TEV-GUS. The novel site was recognized and processed in plants infected by the engineered virus, indicating the presence of excess NIa processing capacity in the cytoplasm. The potential roles of internal NIa processing in TEV-infected cells are discussed.
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PMID:Internal cleavage and trans-proteolytic activities of the VPg-proteinase (NIa) of tobacco etch potyvirus in vivo. 823 Apr 23


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