Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P15088 (mast cell)
14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

gp49 is a Mr 49,000 glycoprotein expressed on the surface of mouse bone marrow-derived mast cells, which are progenitors for the major in vivo mast cell subclasses, typified by intestinal mucosal mast cells and serosal mast cells. The amino-terminal amino acid sequence of gp49 was determined after isolation of the solubilized membrane protein by affinity chromatography with the B23.1 anti-gp49 monoclonal antibody. Redundant oligonucleotides were used to isolate a full-length 1.3-kilobase cDNA from a mouse mast cell library. The predicted amino acid sequence contains a signal peptide of 23 residues, an extracellular domain of 215 residues with three potential sites of N-linked glycosylation, a transmembrane domain of 23 residues, and a cytoplasmic tail of 42 residues. Hybridization of the gp49 cDNA was limited to mRNA extracted from those cell types that also bound the B23.1 monoclonal antibody as assessed by cytofluorographic analyses. The predicted extracellular domain of gp49 contains two regions of 48 and 51 amino acids, each flanked by cysteine residues. Both regions meet criteria for being C2-type domains of the immunoglobulin superfamily based upon the alignment of consensus amino acids and their predicted secondary structure organization. Thus, gp49, a membrane glycoprotein preferentially expressed by the progenitor mast cell population, is a new member of the immunoglobulin superfamily.
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PMID:Molecular cloning of gp49, a cell-surface antigen that is preferentially expressed by mouse mast cell progenitors and is a new member of the immunoglobulin superfamily. 171 1

As assessed by immunoprecipitation analyses, expression of the epitope recognized by the rat mAb B23.1 is approximately sevenfold greater on the surface of mouse IL-3-dependent bone marrow culture-derived mast cells (BMMC) than on serosal mast cells (SMC) obtained directly from the peritoneal cavity. Immunoprecipitation of B23.1 antibody-binding molecules from Na[125I] surface-labeled BMMC and SMC followed by sizing on SDS-polyacrylamide gels under reducing conditions demonstrated that the epitope is located on molecules of 49,000 and 47,500 Mr, respectively. An additional immunoprecipitated molecule of 42,000 Mr was detected from BMMC intrinsically radiolabeled with [35S]methionine, and pulse-chase analyses revealed that this species was a biosynthetic precursor of the 49,000 Mr cell surface form of the Ag. Treatment of the immunoprecipitated 42,000 and 49,000 Mr forms with endoglycosidase F reduced the Mr of both to 37,000, as did intrinsic radiolabeling of BMMC in the presence of tunicamycin, indicating that both the 42,000 Mr precursor form and the 49,000 Mr cell surface molecule (gp49) contained N-linked carbohydrate. Activation of [32P]orthophosphate-labeled BMMC by sensitization with mouse monoclonal IgE anti-TNP and challenge with TNP-BSA or by exposure to the calcium ionophore A23187 elicited the rapid phosphorylation of gp49 but not of its precursor forms, as did treatment of the cells with PMA. Elution of phosphorylated and immunoprecipitated gp49 from SDS-polyacrylamide gels followed by partial acid hydrolysis of the protein and phosphoamino acid analysis by high voltage thin-layer electrophoresis on cellulose plates indicated that serine, but not threonine or tyrosine, was phosphorylated upon stimulation of BMMC with IgE/Ag, calcium ionophore, or PMA. Cholera toxin did not elicit phosphorylation of gp49. These data suggest that gp49, a plasma membrane glycoprotein preferentially expressed by mouse BMMC, may be either directly or indirectly phosphorylated via protein kinase C during mast cell activation-secretion.
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PMID:Activation- and phorbol ester-stimulated phosphorylation of a plasma membrane glycoprotein antigen expressed on mouse IL-3-dependent mast cells and serosal mast cells. 246 32

Mouse mast cells were differentiated and grown by culturing bone marrow cells in medium containing 2 X 10(-10) M purified interleukin 3 (IL 3). The cells obtained were similar in ultrastructure, membrane antigen phenotype, proteoglycan type, and lipid products generated upon immunologic activation to mast cells differentiated in culture by WEHI-3-conditioned medium (WEHI-3-CM) and by concanavalin A (Con A) splenocyte-conditioned medium. Phenotypically, these cells expressed IgE receptors and H-2 antigens and were recognized by a monoclonal antibody (B23.1) that did not react with mouse serosal heparin-containing mast cells. The classic phenotypic markers of mouse T cells or macrophages were not detected. The mouse mast cells differentiated with IL 3 as well as those differentiated in WEHI-3-CM incorporated [35S]sulfate into a nonheparin proteoglycan of 150,000 to 200,000 m.w. Most of the 35S-labeled macromolecules were degraded by chondroitinase ABC to yield only two disaccharides, which co-chromatographed on ascending thin layer chromatography with delta Di-4S and delta Di-diSE; thus, the proteoglycan in these cells is composed of chondroitin sulfate E glycosaminoglycans. After sensitization with monoclonal IgE, washing, and antigen activation, the IL 3 differentiated cells released the preformed mediator beta-hexosaminidase and generated and released two major classes of lipid mediators. The quantities of leukotriene C4 (LTC4), leukotriene B4 (LTB4), and platelet-activating factor (PAF-acether) generated/10(6) cells were 17, 3.0, and 3.1 ng, respectively. The ratio of these three lipid mediators was similar to that obtained from mast cells differentiated in WEHI-3-CM and in Con A-conditioned medium. Thus, T cell-derived IL 3 is the component present in the conditioned media that is required for differentiation and growth of the subclass of mast cells containing chondroitin sulfate E proteoglycan, designated E-MC. The IL 3-dependent E-MC may represent the in vitro counterpart of the T-cell-dependent mucosal mast cell, suggesting in turn that the production of LTC4 and LTB4 and of PAF-acether may play a role in adaptive intestinal immunity to helminthic parasites.
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PMID:Interleukin 3: A differentiation and growth factor for the mouse mast cell that contains chondroitin sulfate E proteoglycan. 619 93

Mouse mast cells express gp49B1, a cell-surface member of the Ig superfamily encoded by the gp49B gene. We now report that by ALIGN comparison of the amino acid sequence of gp49B1 with numerous receptors of the Ig superfamily, a newly recognized family has been established that includes gp49B1, the human myeloid cell Fc receptor for IgA, the bovine myeloid cell Fc receptor for IgG2, and the human killer cell inhibitory receptors expressed on natural killer cells and T lymphocyte subsets. Furthermore, the cytoplasmic domain of gp49B1 contains two immunoreceptor tyrosine-based inhibition motifs that are also present in killer cell inhibitory receptors; these motifs downregulate natural killer cell and T-cell activation signals that lead to cytotoxic activity. As assessed by flow cytometry with transfectants that express either gp49B1 or gp49A, which are 89% identical in the amino acid sequences of their extracellular domains, mAb B23.1 was shown to recognize only gp49B1. Coligation of mAb B23.1 bound to gp49B1 and IgE fixed to the high-affinity Fc receptor for IgE on the surface of mouse bone marrow-derived mast cells inhibited exocytosis in a dose-related manner, as defined by the release of the secretory granule constituent beta-hexosaminidase, as well as the generation of the membrane-derived lipid mediator, leukotriene C4. Thus, gp49B1 is an immunoreceptor tyrosine-based inhibition motif-containing integral cell-surface protein that downregulates the high-affinity Fc receptor for IgE-mediated release of proinflammatory mediators from mast cells. Our findings establish a novel counterregulatory transmembrane pathway by which mast cell activation can be inhibited.
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PMID:Mouse mast cell gp49B1 contains two immunoreceptor tyrosine-based inhibition motifs and suppresses mast cell activation when coligated with the high-affinity Fc receptor for IgE. 885 62

Protein B23 is an abundant, multifunctional nucleolar phosphoprotein whose activities are proposed to play a role in ribosome assembly. Szebeni et al. (1997) showed stimulation of nuclear import in vitro by protein B23 and suggested that this effect was due to a molecular chaperone-like activity. Protein B23 was tested for chaperone activities using several protein substrates. The temperature-dependent and -independent aggregation of the HIV-1 Rev protein was measured using a zero angle light scattering (turbidity) assay. Protein B23 inhibited the aggregation of the Rev protein, with the amount of inhibition proportional to the concentration of B23 added. This activity was saturable with nearly complete inhibition when the molar ratio of B23:Rev was slightly above one. Protein B23 also protected liver alcohol dehydrogenase (LADH), carboxypeptidase A, citrate synthase, and rhodanese from aggregation during thermal denaturation and preserved the enzyme activity of LADH under these conditions. In addition, protein B23 was able to promote the restoration of activity of LADH previously denatured with guanidine-HCl. Protein B23 preferentially bound denatured substrates and exposed hydrophobic regions when complexed with denatured proteins. Thus, by several criteria, protein B23 behaves like a molecular chaperone; these activities may be related to its role in ribosome biogenesis.
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PMID:Nucleolar protein B23 has molecular chaperone activities. 1021 37

Atractylodin is one of the major constituents of the rhizome of Atractylodes lancea, which is widely used in Korean traditional medicine as a remedy for the treatment of gastritis and gastric ulcers. Despite of a major constituent of widely used botanical to treat inflammatory responses little is known about anti-inflammatory effect of atractylodin in the human mast cell (HMC-1). Hence, we evaluated the effect of atractylodin on the release of IL-6, the involvement of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) and mitogen-activated protein kinases (MAPKs) in phorbol-12-myristate-13-acetate and A23187-induced HMC-1. In addition, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), phospholipase C (PLC) gamma 1, and AKT phosphorylation relevant to NPM-ALK signal pathway were assessed. IL-6 levels in the HMC-1 stimulated by phorbol-12-myristate-13-acetate and A23187 were apparently decreased by the treatment of atractylodin. Concurrently, atractylodin not only inhibited the phosphorylation of NPM-ALK, but also suppressed the phosphorylation of JAK2, STAT3, PLC gamma 1, and AKT. Furthermore, the activated mitogen-activated protein kinases (MAPKs) by phorbol-12-myristate-13-acetate and A23187 were inhibited by atractylodin. These results suggested that atractylodin might have a potential regulatory effect on inflammatory mediator expression through blockade of both the phosphorylation of MAPKs and the NPM-ALK signaling pathway.
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PMID:Atractylodin Inhibits Interleukin-6 by Blocking NPM-ALK Activation and MAPKs in HMC-1. 2779 26