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)

Human platelet plasma membranes were isolated with polylysine beads according to the technique developed by Jacobson and Branton (1977, Science [Wash. D. C.] 195:302--304). Lactoperoxidase-catalyzed surface iodination revealed that ninefold greater 125I specific activity was associated with the membranes isolated on beads than with whole platelets. Enrichment in the bead membrane preparation of the activities of membrane marker enzymes, bis(p-nitrophenyl)phosphate phosphodiesterase and Na,K-ATPase, was 8.0 and 4.4, respectively. Contamination with enzymes of other organelles, cytochrome oxidase and beta-glucuronidase, was relatively low as compared with membranes isolated by sucrose gradient centrifugation. Analysis by SDS polyacrylamide gel electrophoresis showed that a full complement of surface glycoproteins was present on the membranes isolated with polylysine beads. The polylysine bead technique is a rapid, reproducible and efficient method for the preparation of relatively pure platelet plasma membranes.
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PMID:Isolation of human platelet plasma membranes with polylysine beads. 22 8

Skin excisions were investigated in 5 patients with verified mycosis fungoides. Findings yielded by light and electron microscopy helped to confirm the findings anticipated, and were correlated with histochemical observations. One of the cases involved a substantially higher activity of lysosomal enzymes, particularly KF and beta-glucuronidase in the skin infiltrate mycotic cells. In the other cases, this sort of activity was low. The significance of high ATPase activity in the peripheral cell membrane remains unclear. In one case, involvement in the T lymphocyte series was confirmed by the formation of rosettes.
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PMID:[Histological, electron-optical and histochemical findings in mycosis fungoides]. 69 9

Seven spleens and two peripheral blood specimens from eight patients with hairy cell leukemia were examined with enzyme cytochemical and histochemical methods. Hairy cells consistently exhibited acid phosphatase and tartrate-resistant acid phosphatase. However, nonspecific esterases characteristic of monocytes and histiocytes were consistently absent or very weak. beta-glucuronidase and cytoplasmic membrane-bound ATPase were positive in four cases, suggesting a possible relationship to the B-lymphocytic series. Fundamental splenic changes were accumulation of hairy cells and benign macrophages within the pulp cords, with resulting extreme expansion of the cords. Abnormally well developed ellipsoids were identified around the sheathed arteries within the cords. Sinuses, specifically delineated with the NASDA reaction, were atrophic and often destroyed. No cytogeneologic relationship was found between sinus endothelial cells and hairy cells. The pulp cords are the primary site of involvement of the spleen in hairy cell leukemia. A simultaneous proliferation of neoplastic cells, histiocytes and reticulum fibers accounts for the splenomegaly and clinical hypersplenism characteristic of the disease.
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PMID:Hairy cell leukemia. Enzyme histochemical characterization, with special reference to splenic stromal changes. 87 31

We used a combination of subcellular fractionation and lactoperoxidase-mediated iodination to examine the polypeptide compositions of three hepatocyte endocytic compartments: early endosomes, late endosomes, and lysosomes. A chemical conjugate of asialoorosomucoid and lactoperoxidase which binds specifically to asialoglycoprotein receptors was perfused through isolated rat livers at 37 degrees C. Subcellular fractions enriched in various endocytic compartments were then isolated by differential and isopycnic centrifugation, and the lactoperoxidase moiety of the internalized conjugate was used to catalyze the iodination of lumenal-facing proteins. The 125I profiles of early and late endosomes were strikingly similar after gel electrophoresis. Using immunoprecipitation, we directly identified and compared the relative amounts of the Na+,K(+)-ATPase and several different acid hydrolases and membrane receptors in all three fractions. The asialoglycoprotein receptor and the low density lipoprotein related protein were approximately nine times more abundant in early endosomes than late endosomes, suggesting that they recycle from early endosomes. In addition, cathepsin D, but not cathepsin L, beta-glucuronidase, and lgp 120, was detected in early endosomes; however, all of these molecules were detected in lysosomes. Our findings provide strong evidence that early endosomes mature into late endosomes and that there is either selective delivery or selective retention of hydrolases at discrete points in the endocytic pathway.
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PMID:Lumenal labeling of rat hepatocyte endocytic compartments. Distribution of several acid hydrolases and membrane receptors. 131 3

Gastric mucosal PG E2 receptors are the common antisecretory working point of all prostanoid types and may also be involved in "protective" effects. We investigated the subcellular localization of these receptors, as measured by displaceable 3H-PG E2 binding, and identified different organelles by monitoring the activities of specific marker enzymes. Porcine mucosal homogenates were subdivided by differential centrifugation into fractions P1 (1000 x g), P2 (20,000 x g), P3 (300,000 x g) and the supernatant S1. P3 was further fractionated over a series of sucrose step gradients. Mitochondria and lysosomes were enriched in P2 (maximum specific activities of cytochrome-c-oxidase of beta-glucosidase, beta-glucuronidase, beta-galactosidase, respectively). Plasma membranes (alkaline phosphatase, gamma-glutamyl-transpeptidase, 5-nucleotidase), tubulovesicles (H+/K(+)-ATPase) and rough endoplasmic reticulum (NADPH-cytochrome-c-reductase) were mainly found in P3, which also contained the majority of 3H-PG E2 binding sites. In contrast, prostanoid binding was barely detectable in S1. Density fractionation of P3 revealed that 3H-PG E2 binding sites shared a similar sedimentation profile with plasma membranes and tubulovesicular markers. No or negative correlation was found with lysosomes, rough endoplasmic reticulum and mitochondria. We conclude that mucosal PG E2 receptors are predominantly located at the cell surface. This supports the view that prostanoids inhibit gastric secretion through membrane receptors, but gives no clue for intracellular "protective" working points.
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PMID:Subcellular localization of prostaglandin E2 receptors in the gastric mucosa. 134 83

The present studies indicate that 50 nM-10 microM-staurosporine increased cytosolic free Ca2+ concentrations ([Ca2+]i) of fura-2-loaded neutrophils in a non-linear manner. The rise in [Ca2+]i was rapid, reaching a plateau (e.g. to 0.4 microM with 1 microM-staurosporine) within 30 s, and was maintained for more than 20 min. Pretreating cells with pertussis toxin had no effect on this reaction. The elevation of [Ca2+]i was insensitive to extracellular Ca2+ concentrations and was due entirely to mobilization of intracellular Ca2+ stores. Mn(2+)-quench studies confirmed the absence of Ca2+ influx. No Ca2+ efflux occurred in staurosporine-treated cells. In combination studies, staurosporine potentiated Ca2+ influx induced by N-formylmethionyl-leucyl-phenylalanine (FMLP) and did not block Ca2+ efflux associated with peptide stimulation of neutrophils. Studies with permeabilized cells showed that staurosporine did not directly release intracellular Ca2+ stores, nor did it affect the sequestration of Ca2+ by a Ca2+/ATPase pump. A radioligand-binding assay failed to detect changes in the level of inositol 1,4,5-trisphosphate in neutrophils incubated with less than or equal to 1 microM-staurosporine, but in cells treated with 10 microM-staurosporine the assay recorded a transient increase in this second messenger similar to that induced by FMLP. Finally, lysozyme, but not beta-glucuronidase, was released from staurosporine-treated cells. The present results suggest that staurosporine increased [Ca2+]i by indirectly mobilizing internal Ca2+ stores. Staurosporine suppression of Ca2+ efflux and generation of a persistent signal may account for the maintained elevation of [Ca2+]i.
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PMID:Staurosporine clamps cytosolic free Ca2+ concentrations of human neutrophils. 157 94

Bone resorption plays an important role in bone modeling and remodeling. Osteoclasts are the cells responsible for the bone resorption. Osteoclasts are located on endosteal bone surfaces and on the periosteal surface beneath the periosteum. They are multinucleated giant cells highly polarized in their morphology and function. Among the proximal surface, the membrane and the area of the cytoplasm directly oppose to the bone surface, which are specialized into two regions. A central region consisting of many irregular cytoplasmic processes and infoldings, the ruffled border, is known to be the active site of bone resorption. Surrounding the ruffled border, a second region, the clear zone provides an area of close attachment to the mineralized bone surface. The osteoclasts secrete a large amount of protons by the action of H(+)-pump on the ruffled border into the sealed resorption cavity, resulting in the acidified microenvironment under which condition the bone matrix is dissolved. Protons are provided by the intracellular action of carbonic anhydrase. Following the secretion of the protons, several ion-transporting systems, i.e., carbonate-chloride exchanger, chloride-channel, Ca(2+)-transport systems, Na+/K(+)-ATPase, and voltage-dependent Ca(2+)-channel, are sequentially operated on both apical and basolateral cytoplasmic membranes. In addition, osteoclasts contain a large amount of lysosomal enzymes (cathepsin C, beta-glycerophosphatase, beta-glucuronidase, etc.), which contribute to degrade the bone organic matrices exposed in the resorption cavity. These enzymes bind to the mannose-6-phosphate receptor on Golgi apparatus, are transported to the ruffled border and are secreted into the extracellular compartment in an exocytotic manner. Osteoclasts also have a high tartrate-resistant acid phosphatase activity which is currently used as a marker enzyme osteoclastic differentiation. Osteoclasts are considered to develop from hematopoietic stem cells. So far, the following four different pathways of the differentiation of osteoclast are proposed: The precursors of osteoclast develop (1) from multilineage hematopoietic cells via a completely separate differentiation line, (2) from granulocyte macrophage-colony forming cells, (3) from committed but proliferative monocyte-macrophage, and (4) from mature and unproliferative monocyte-macrophage. However, the differentiation line of the osteoclasts has still to be elucidated. The formation of osteoclasts as well as that of other hematopoietic cells is strongly regulated by many cytokines [interleukin (IL)-1,IL-3,IL-6, M-colony stimulating factor (CSF), and GM-CSF]. 1,25-Dihydroxyvitamin D3 and parathyroid hormone also stimulate the differentiation of osteoclast precursors. However, the mature osteoclasts do not possess the receptors for these hormones.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Osteoclasts in bone metabolism]. 175 56

Metabolic energy is required for the loading of sucrose into the phloem and translocation of sugars throughout the plant. The proton electrochemical gradient generated by a plasma membrane proton pump (H(+)-ATPase) is thought to provide energy for these processes. The plasma membrane H(+)-ATPase is encoded by a multigene family in Arabidopsis thaliana. Here we characterize the expression of isoform AHA3 (Arabidopsis H(+)-ATPase isoform 3). The AHA3 mRNA start site was mapped and 464 bp of the putative upstream regulatory region sequenced. A translational fusion of AHA3 to the beta-glucuronidase (GUS) reporter gene was constructed and used to generate transgenic Nicotiana and Arabidopsis plants. Using a histochemical stain, expression of the AHA3/GUS fusion was found predominantly in phloem cells of leaves, stems, roots, and flowers. Biochemical measurements of GUS activity in pith and vascular explants confirmed the histochemical localization. Our results support the hypothesis that a proton pump is present in phloem cells, possibly providing energy to drive plasma membrane cotransport systems required for phloem loading and translocation of photosynthates. In addition to AHA3/GUS expression in phloem, expression was observed in pollen and regions of the ovule, tissues whose physiological functions correlate with a requirement for high levels of solute transport.
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PMID:Evidence for a plasma membrane proton pump in phloem cells of higher plants. 184 77

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

The distribution of enzymes and laminin was examined in ileal tissue from pigs suffering from intestinal adenomatosis to reveal the nature of the lesion. A disruption of the normal and specific pattern of distribution was found. Thus, the normal ileal epithelium was characterised by brush border enzymes: alkaline phosphatase, magnesium-dependent adenosine triphosphatase (Mg-ATPase), fluoride resistant acid phosphatase and 5'-nucleotidase; enzymes of the basolateral border: Mg-ATPase; and cytoplasmic enzymes: beta-glucuronidase, non-specific esterase and acid phosphatase. Subepithelial fibroblasts seemed to be characterised by 5'-nucleotidase. Laminin was present as a continuous band under the surface and crypt epithelium, somewhat thicker in the former. In contrast, the branching proliferating crypts of intestinal adenomatosis largely lacked enzymes characteristic of both villus and crypt cells. Reactions for the subepithelial components, laminin and fibroblasts were also reduced. The deficient differentiation of the epithelial as well as subepithelial components in porcine intestinal adenomatosis distinguish the condition from crypt hyperplasia and indicate an adenoma-like character.
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PMID:Cell differentiation in intestinal adenomatosis of pigs studied by histochemistry of laminin and enzymes of epithelial and subepithelial tissue. 214 4


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