Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using a synthetic peptide that encompasses the zinc finger domain of the eukaryotic transcription factor Sp1, we produced a number of monoclonal antibodies that specifically reacted with the target antigen. Analysis by competitive inhibition assay of five of the monoclonal antibodies revealed that they all recognized a dominant epitope in the synthetic peptide and reacted strongly to recombinantly synthesized beta-galactosidase-Sp1 fusion polypeptide. To determine cellular distribution of Sp1-like molecules, cytoplasmic and nuclear proteins from human lung fibroblasts (HFL-1) and a human rhabdomyosarcoma cell line (A204) were immunoblotted and reacted with our antibodies. In addition to the well characterized 95 Kd and 105 Kd proteins, considered to be the authentic Sp1 polypeptide, a number of other cellular proteins reacted with these antibodies. Immunofluorescence staining of the cells with mAb to the zinc finger of Sp1 also revealed cell-specific differences in intracellular distribution of Sp1-like molecules. Both cytoplasmic and nuclear staining was readily observed in the rhabdomyosarcoma cells. In contrast, while some HFL-1 cells exhibited staining of only cytoplasm, both cytoplasmic and nuclear immunofluorescence was seen in others.
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PMID:Generation of monoclonal antibodies to the zinc finger domain of the eukaryotic transcription factor Sp1. 201 Nov 20

The binding sites for human interferon-alpha (IFN-alpha) have been characterized on human lymphoblastoid, melanoma, rhabdomyosarcoma, and cervical carcinoma cells. Crosslinking of iodinated-recombinant DNA-derived IFN-alpha-Con1, an analog of the known IFN-alpha subtypes, to the cell surface with disuccinimidyl suberate yielded four IFN-receptor complexes of 118, 138, 159, and 260 kD on all cell lines that specifically bind IFN-alpha. Since IFN-alpha exists in solution as monomers, dimers, and trimers, and the three lower molecular weight IFN-alpha-receptor complexes differ by the molecular weight of IFN-alpha (20 kD), this suggests that the human IFN-alpha receptor of 100 kD binds more than one molecule of IFN-alpha. The higher molecular weight complex of 260 kD may result from dimerization of the receptor. None of these complexes was observed in a rhabdomyosarcoma subclone that does not specifically bind IFN-alpha. Pretreatment of cells with trypsin abolished the formation of these complexes. Pretreatment of cells with neuraminidase did not reduce IFN-alpha binding, but increased the electrophoretic mobility of all four IFN-alpha-receptor complexes. Other glycosidases (i.e., mannosidase, beta-galactosidase, and endoglycosidase F) had no effects on IFN-alpha binding or mobility of complexes. Thus, although the IFN-alpha receptor is a glycoprotein, the glycosylated portion is apparently not part of the IFN-alpha-binding domain. The formation of IFN-alpha-receptor complexes is independent of the duration of incubation with IFN (from 5 min to 1 h at 15 degrees C).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of interferon-alpha binding sites on human cell lines. 246 92

The functional role of human tumor necrosis factor receptor (TNFR) p75 was studied by the use of TNFR p75-specific agonistic antibodies. Human SW480T adenocarcinoma cells, stably transfected with a reporter construct containing beta-galactosidase under the control of human cytomegalovirus immediate early enhancer, were stimulated with anti-TNFR p75 polyclonal antiserum or monoclonal antibodies followed by measurement of beta-galactosidase activity and analysis by electrophoretic mobility shift assays. It was found that cross-linking of TNFR p75 led to strong induction of the human cytomegalovirus enhancer as well as activation of nuclear factor-kappa B (NF-kappa B). Stimulation of TNFR p75 also mediated activation of NF-kappa B in human KYM-1 rhabdomyosarcoma cells but not in other cell types such as U937 and HL-60 monocytic cells or in Eahy 926 endothelial cells. NF-kappa B activation induced by TNFR p75 was delayed approximately 15 min compared with NF-kappa B activation induced by TNFR p55, indicating that the two TNFRs activate NF-kappa B through different signaling pathways. The data presented in this study identify intracellular responses mediated by TNFR p75 which have not been reported previously and suggest that TNFR p75-induced activation of NF-kappa B is strictly cell type-specific.
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PMID:Tumor necrosis factor receptor p75 mediates cell-specific activation of nuclear factor kappa B and induction of human cytomegalovirus enhancer. 812 5

We examined a panel of cell lines for the expression of the myogenic proteins myoD and myogenin. High level expression of both proteins was seen in rhabdomyosarcoma (RMS). To determine whether promoter elements from these genes could direct RMS cell-specific expression, we generated reporter constructs containing one or two copies of the myoD enhancer coupled to the SV40 promoter. Transient transfection reporter assays confirmed the selective expression of beta-galactosidase (beta-gal) in 8 RMS cell lines. In contrast, very low expression from the myoD enhancer/SV40 promoter was detected in four non-RMS cell lines. To determine whether the hybrid promoter could elicit RMS-specific cytotoxicity, a mammalian expression vector containing the herpes simplex virus thymidine kinase (HSVtk) under control of the hybrid myoD enhancer/SV40 promoter was constructed. After electroporation into several cell lines, selective RMS cell kill was observed after treatment with ganciclovir. These data suggest that in vivo tumor-specific expression of HSVtk from the myoD enhancer/SV40 promoter may provide an alternative to current chemotherapy.
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PMID:Rhabdomyosarcoma-specific expression of the herpes simplex virus thymidine kinase gene confers sensitivity to ganciclovir. 969 70

DNase X is the first mammalian DNase to be isolated that is homologous to DNase I. In this study, we have examined its function using a novel monoclonal antibody and showed it to be expressed on the cell surface as a glycosylphosphatidylinositolanchored membrane protein. High level expression was observed in human muscular tissues and in myotubes obtained in vitro from RD rhabdomyosarcoma cells. We observed that RD myotubes incorporated a foreign gene, lacZ, by endocytosis but that expression of the encoded coding product, beta-galactosidase, was strongly inhibited. Overexpression of DNase X inhibited endocytosis-mediated gene transfer, whereas knockdown of DNase X with small interfering RNA had the opposite effect. These results reveal that DNase X provides a cell surface barrier to endocytosis-mediated gene transfer.
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PMID:DNase X is a glycosylphosphatidylinositol-anchored membrane enzyme that provides a barrier to endocytosis-mediated transfer of a foreign gene. 1741 4