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

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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)

Male BALB/C mice were injected intraperitoneally with 2.5 i.u. of gonadotrophin. After the injection, increase of beta-glucuronidase activity was first observed in the microsomal fraction. By 36h 45-50% of the total homogenate activity was found in the microsomal fraction compared with 20-25% in the control microsomal fraction. From 36 to 80h not only microsomal beta-glucuronidase but also lysosomal beta-glucuronidase increased progressively. After 69h stimulation with 2.5 i.u. of gonadotrophin, d-[1-(14)C]glucosamine or l-[U-(14)C]leucine was injected intraperitoneally. After a further 3h the kidneys were homogenized and five particulate fractions were prepared by differential centrifugation. The beta-glucuronidase in the microsomal and lysosomal fractions was released respectively by ultrasonication and by freezing and thawing treatment. The enzyme was purified by organic-solvent precipitation and by sucrose-density-gradient centrifugation. The results demonstrated the incorporation of these two labels into the mouse renal beta-glucuronidase. The microsomal beta-glucuronidase was much more radioactive than the lysosomal enzyme and approx. 80% of the newly synthesized enzyme appeared in microsomes and approx. 20% of that was found in lysosomes at this period. These results suggest that the mouse renal beta-glucuronidase is a glycoprotein and that the newly synthesized enzyme is transported from endoplasmic reticulum to lysosomes.
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PMID:Incorporation of [14C] glucosamine and [14C] leucine into mouse kidney beta-glucuronidase induced by gonadotrophin. 542 Sep 51

Lysosomal hydrolases produce degradation of glomerular basement membrane and may play a key role in catabolism of glycoproteins of extracellular matrix in glomeruli. Therefore we investigated activities of some lysosomal enzymes and stability of lysosomes in glomeruli of normal and nephrotic rats. Nephrosis was induced in rats by single injections of puromycin aminonucleoside. In glomeruli from nephrotic rats we found lower activities of beta-fucosidase and arylsulfatase, but activity of acid phosphatase was higher compared with control rats. Osmotic stability of lysosomes measured by release of beta-glucuronidase was decreased in nephrotic rats. Abnormal activity of lysosomal enzymes and altered physiology of lysosomes in glomeruli may be a pathogenic factor in the altered glycoprotein metabolism in nephrotic syndrome and perhaps also in other glomerular diseases.
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PMID:Glomerular lysosomal enzymes in aminonucleoside nephrosis. 617 16

Electron-dense material in clear synaptic vesicles in rat cerebral cortex and neuromuscular junctions of frog cutaneous pectoris muscle was demonstrated by using ferrocenyl cationics. Electron-dense spots were usually attached to the inner surface of the vesicular membrane. Control experiments (treatment with Triton X-100 or cetylpyridinium chloride; enzyme digestion with trypsin, hyaluronidase, neuraminidase, sulfatase and beta-glucuronidase) suggested that the electron-dense material is a glycoprotein.
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PMID:Demonstration of electron-dense material in clear synaptic vesicles using cationic ferrocenyl compounds. 633 45

The effect of chloroquine, an inhibitor of intralysosomal catabolism, on the synthesis, transport, and degradation of cell-coat glycoproteins in absorptive cells of cultured human small-intestine tissue was investigated by morphometrical, autoradiographical, and biochemical methods. Neither synthesis nor transport of cell-coat material was affected by the drug, but culturing of the absorptive cells in the presence of chloroquine led to a dose- and time-dependent enlargement of the dense bodies; other cell structures showed no alterations. 3H-fucose-labelled material accumulated in the dense bodies of the absorptive cells of these cultures. Since no increase of beta-glucuronidase and acid phosphatase activity (both lysosomal enzymes of glycoprotein nature) was found, this accumulation of radiolabeled material can be explained as a chloroquine-mediated inhibition of the degradation of cell-coat glycoproteins. These macromolecules probably enter the lysosome-like bodies by a crino-phagic mechanism, i.e., fusion of these organelles with the apical vesicles and tubules involved in intracellular transport. These findings suggest that the lysosome-like bodies have a function in the regulating of cell-coat glycoprotein transport in human intestinal absorptive cell, i.e., the degradation of excess cell-coat material.
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PMID:The effect of chloroquine on lysosomal function and cell-coat glycoprotein transport in the absorptive cells of cultured human small-intestinal tissue. 726 Oct 28

The HRGP4.1 gene, which encodes a cell wall hydroxyproline-rich glycoprotein, was isolated from a genomic library of bean (Phaseolus vulgaris L.). Two transcripts, one induced by wounding and one by elicitation, were transcribed from the same initiation site. The gene encodes a polypeptide of 580 amino acids with the amino terminal half consisting of repeats of the sequence serine-(proline)4-lysine-histidine-serine-(proline)4-(tyrosine)3-histidi ne and the carboxyl-terminal half composed of repeats of the sequence serine-(proline)4-valine-tyrosine-lysine-tyrosine-lysine. A 964-bp upstream promoter fragment was translationally fused to the beta-glucuronidase reporter gene (Escherichia coli uidA) and transferred into tobacco by Agrobacterium tumefaciens-mediated leaf disc transformation. Analysis of beta-glucuronidase activity showed that wounding caused local activation of the HRGP4.1 promoter in the phloem. Infection by tobacco mosaic virus was a less effective inducer than wounding. Stress induction was superimposed on tissue-specific developmental expression in stem nodes and root tips, suggesting that HRGP4.1 may have specific structural roles in development as well as protective functions in defense. Deletion analysis showed that control of tissue specificity and wound inducibility lies in a region between -94 and -251 relative to the transcription start site and that activation by infection lies outside that region.
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PMID:Stress activation of a bean hydroxyproline-rich glycoprotein promoter is superimposed on a pattern of tissue-specific developmental expression. 748 Mar 31

The development of experimental cholecystitis produced by lysophosphatidylcholine is associated with reversal of the normal absorptive characteristics of gallbladder mucosa, resulting in the intraluminal accumulation of water, glycoprotein, and protein. The purpose of the present study was to attempt to ascertain if the protein leaks into the lumen because of the cytolytic properties of lysophosphatidylcholine or if it is due to an active secretory process and to characterize the protein produced. Experiments were performed on anesthetized cats undergoing gallbladder perfusion with and without lysophosphatidylcholine. The amount of protein in the perfusate was measured and albumin clearance from blood to gallbladder lumen was calculated with and without the administration of vesicular transport inhibitors. In separate experiments, control and lysophosphatidylcholine (LPC) produced gallbladder perfusates were collected and the protein subjected to SDS-PAGE to ascertain the nature of the protein secreted. Inhibitors of both microtubular and microfilament activity decreased the protein accumulation and clearance produced by lysophosphatidylcholine. Gallbladder white blood cell accumulation and inflammation as evaluated by beta-glucuronidase and prostaglandin E levels were not significantly altered by cytochalasin or colchicine administration. Lysophosphatidylcholine also produced significant increases in perfusate LDH levels. The protein produced was primarily a 66-kDa protein. Transfer of the protein to a nitrocellulose membrane and immunoblotting with anti-albumin antibody demonstrated that the protein was albumin. The results suggest that during the development of cholecystitis, lysophosphatidylcholine produces albumin accumulation in the gallbladder primarily by inducing an active secretory process resulting in gallbladder distension.
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PMID:Gallbladder mucosal protein secretion during development of experimental cholecystitis. 772 80

beta-Glucuronidase is retained within the endoplasmic reticulum (ER) via complex formation with esterase-22 (egasyn), which in turn has a COOH-terminal HTEL ER retention sequence. To identify the regions of glucuronidase that interact with egasyn, complex formation was assayed in COS cells cotransfected with egasyn cDNA and with either deletion constructs of glucuronidase or with constructs containing specific glucuronidase propeptide sequences appended to the carboxyl terminus of a rat secretory protein alpha 1-acid glycoprotein. The region of glucuronidase essential for complex formation is a linear octamer sequence at the COOH terminus of the propeptide. A portion of this octamer is similar to a sequence near the reactive site of serpins. This and associated data indicate that an interaction related to that between serine proteinases and their serpin inhibitors retains beta-glucuronidase within the ER. Further, attachment of this octamer sequence provides an alternative method of targeting proteins to the ER lumen of any cell that contains egasyn. These and related results demonstrate that complex formation with esterases/proteinases within the ER is important in the subcellular targeting and/or processing of certain proteins.
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PMID:The beta-glucuronidase propeptide contains a serpin-related octamer necessary for complex formation with egasyn esterase and for retention within the endoplasmic reticulum. 774 42

We have expressed useful amounts of three recombinant proteins in a new eukaryotic host/vector system. The cellular slime mold Dictyostelium discoideum efficiently secreted two recombinant products, a soluble form of the normally cell surface associated D. discoideum glycoprotein (PsA) and the heterologous protein glutathione-S-transferase (GST) from Schistosoma japonicum, while the enzyme beta-glucuronidase (GUS) from Escherichia coli was cell associated. Up to 20mg/l of recombinant PsA and 1mg/l of GST were obtained after purification from a standard, peptone based growth medium. The secretion signal peptide was correctly cleaved from the recombinant GST- and PsA-proteins and the expression of recombinant PsA was shown to be stable for at least one hundred generations in the absence of selection.
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PMID:Production and secretion of recombinant proteins in Dictyostelium discoideum. 776 51

Envelope glycoproteins of human immunodeficiency viruses (HIV-1 and HIV-2) can interact with high-mannose glycans and with the mannosyl or N-acetylglucosaminyl core of complex-type oligosaccharidic structures. HIV-1 glycoproteins also specifically bind sulphated polysaccharides such as dextran sulphate (DS) and heparin. Here, we show that the latter property is shared by HIV-2 recombinant gp140 (rgp140) precursor glycoprotein. Binding of rgp140 and of corresponding rgp160 of HIV-1 to heparin- and DS-substituted (sulphated dextran beads; SDB) affinity matrices was inhibited by the soluble specific ligand and also by fetuin, asialofetuin or the anionic simple carbohydrate derivative mannose-6-phosphate (M6P). Interaction of HIV-1 rgp120 subunit with the two affinity matrices was also inhibited by M6P, but only rgp120 binding to heparin-agarose, and not that to SDB, was affected by fetuin and asialofetuin. These results suggest that HIV-1 and HIV-2 envelope glycoproteins presumably display different sulphated polysaccharide and carbohydrate recognition sites. Some of these may be common or in close proximity: with respect to rgp160, for example, the sites may be common on the gp41 moiety and/or in a region of gp120 which would be more accessible when expressed on rgp160 than on processed gp120, while they may be distinct on the cleaved gp120 subunit. Finally, because M6P is a marker of lysosomal enzymes, we verified that HIV-1 and HIV-2 envelope glycoproteins could specifically bind in a M6P-inhibitable manner to a representative lysosomal enzyme, bovine liver beta-glucuronidase coupled to agarose, suggesting that they may possibly interfere with lysosomal enzyme sorting in HIV-infected cells.
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PMID:Interactions of HIV-1 and HIV-2 envelope glycoproteins with sulphated polysaccharides and mannose-6-phosphate. 818 46

Egasyn is localized within the lumen of the endoplasmic reticulum (ER) where it complexes with and thus causes sequestration of a considerable portion of beta-glucuronidase. Egasyn has an HTEL sequence at its carboxyl terminus rather than the KDEL sequence that serves as a retention signal for many ER lumenal proteins. To determine whether the HTEL sequence acts as an ER retention signal and/or functions in complex formation, HTEL-deleted egasyn was expressed in mammalian cell lines. The majority of HTEL-deleted egasyn was secreted, while wild type egasyn was retained in the ER. Furthermore, the egasyn HTEL sequence, when added to the carboxyl termini of two secretory proteins, mouse esterase, Es-N, and rat alpha 1-acid glycoprotein (AGP), caused retention of both proteins within the ER, demonstrating that the HTEL sequence is both necessary and sufficient for retention of egasyn and, by extension, the egasyn-glucuronidase complex within the ER. Other carboxyl terminal tetrapeptides including HIEL and HVEL, naturally occurring in other ER lumenal proteins, were also sufficient for ER retention of AGP, while HTEHT and HTEHK were inefficient in ER retention. The HTEL sequence, in contrast, is not required for egasyn-glucuronidase complex formation. Further, the complex is apparently unstable outside the ER since it was not visible in the medium of cells transfected with egasyn lacking the HTEL sequence despite abundant secretion of this egasyn. These results show that it is possible to localize proteins within the lumen of the ER if they form complexes with ER lumenal proteins containing an intrinsic ER retention sequence.
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PMID:The signal for retention of the egasyn-glucuronidase complex within the endoplasmic reticulum. 834 16


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