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

Vaccinia virus (VV) expression vector was used to clone the genes for coding alpha and beta subunits of human chorionic gonadotropin (hCG). Recombinant viruses VSL3 and VSS1 containing these genes were selected as blue coloured plaques on the basis of co-expression of Escherichia coli beta-galactosidase in the infected cells. CV-1 cells when infected with VSL3 or VSS1 secreted 2.4 and 1.8 micrograms of alpha and beta hCG subunits, respectively, per 3 x 10(6) cells after 24 h of infection. The subunit proteins expressed individually had immunoreactivity with monoclonal and polyclonal antibodies specific to hCG. The subunit hormonal peptides associated with each other during co-infection to form the complete hCG dimer, which was biologically active as evident from the induction of steroidogenesis in a mouse Leydig cell system.
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PMID:Expression of biologically active human chorionic gonadotropin and its subunits by recombinant vaccinia virus. 247 9

Binary developmental decisions and homeostatic regulation by steroids require negative transcriptional regulation to balance steroid-mediated stimulatory effects. Human glucocorticoid receptor mutants were used to identify regions important for trans-repression of the gene encoding the alpha subunit of chorionic gonadotropin. While the amino terminus is not critical, the DNA binding and ligand binding domains are required for efficient repression. However, the function of the carboxyl terminus can be substituted by a polypeptide from the human mineralocorticoid receptor or beta-galactosidase gene. The function of these fusion repressors supports the model that the human glucocorticoid receptor negatively regulates transcription via a steric hindrance mechanism. These results suggest a potentially general strategy for creation of sequence-specific transcriptional repressors.
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PMID:Transcriptional inhibition by a glucocorticoid receptor-beta-galactosidase fusion protein. 314 38

A two-site sandwich enzyme immunoassay for human chorionic gonadotropin (hCG) employing monoclonal antibodies directed against beta- and alpha-subunits is described. Monoclonal anti-beta-hCG antibody was used for coating microtitration plates and monoclonal anti-alpha-hCG antibody labelled with 1 of the 3 enzymes namely horseradish peroxidase, alkaline phosphatase or beta-galactosidase was used as tracer. The assay is able to detect up to 1 ng hCG/ml. No significant difference was observed with respect to sensitivity and range of assay with the 3 enzymes. The assay can be performed as a 'two-step' assay or reduced to a 'one-step' procedure with a linear relationship between absorbance and hormone concentration up to 31.25 ng hCG/ml. Beyond these concentrations an inflection of the dose curve was observed. This can, however, be avoided by increasing the concentration of antibody-enzyme conjugate. A higher sensitivity enabling detection up to 0.25 ng hCG/ml was attained in the sandwich enzyme immunoassay with the use of biotin-avidin interface. The hCG values obtained on 47 human urine samples either by the 'one-step' or 'two-step' procedure were similar with a correlation coefficient of 0.996. Results obtained by 'two-step' sandwich enzyme immunoassay on 22 human urine samples correlated well (r = 0.968) with the values obtained by radioimmunoassay.
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PMID:Solid-phase sandwich enzyme immunoassays of human chorionic gonadotropin using monoclonal antibodies. 390 69

Experiments on white male rats were made to study and compare the action of hormonal drugs (testosterone propionate, retabolil and chorionic gonadotropin) on lysosomal enzymes of different tissues. There were differences in the changes in the activity of acid phosphatase, ribonuclease, cathepsins and beta-galactosidase after a single administration of testosterone and after a course of drug treatment. Retabolil and chorionic gonadotropin acted on lysosomal enzymes of spermatic vesicles similarly to testosterone given in a single dose. As far as the activity of liver cathepsins and beta-galactosidase is concerned retabolil was found to produce an opposite effect as compared to that of testosterone.
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PMID:[Effect of hormonal preparations on lysosome enzyme activity in rat tissues]. 686 93

The baculovirus system is an extremely powerful tool for expression of heterologous genes in eukaryotic environment. A multiple expression vector, pBacUCmP3, was constructed which harbored two copies of the Autographa californica nuclear polyhedrosis virus very late gene promoter and the Drosophila melanogaster 70-kDa heat-shock protein (hsp70) promoter with downstream unique restriction sites for cloning of three independent foreign genes. Co-transfection of pBacUCmP3 with Bsu36I-linearized viral DNA yields recombinant progeny viruses at very high frequencies. The utility of this multiple expression transfer vector was demonstrated using three heterologous reporter genes encoding the beta-subunit of the human chorionic gonadotropin hormone, firefly luciferase and the bacterial beta-galactosidase (beta Gal) enzyme. The expression of reporter genes, monitored at various times post-infection, confirmed that while beta-Gal synthesis was under the transcriptional control of the hsp70 promoter, the beta hCG and Luc proteins were synthesized as a function of polyhedrin promoter activation profile. This vector will be useful for multiple synthesis of proteins at different time points.
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PMID:A recombination-efficient baculovirus vector for simultaneous expression of multiple genes. 866 74

We have developed RNA molecules capable of effecting spliceosome-mediated RNA trans-splicing reactions with a target messenger RNA precursor (pre-mRNA). Targeted trans-splicing was demonstrated in a HeLa nuclear extract, cultured human cells, and H1299 human lung cancer tumors in athymic mice. Trans-splicing between a cancer-associated pre-mRNA encoding the beta-subunit of human chorionic gonadotropin gene 6 and pre-trans-splicing molecule (PTM) RNA was accurate both in vitro and in vivo. Comparison of targeted versus nontargeted trans-splicing revealed a moderate level of specificity, which was improved by the addition of an internal inverted repeat encompassing the PTM splice site. Competition between cis- and trans-splicing demonstrated that cis-splicing can be inhibited by trans-splicing. RNA repair in a splicing model of a nonfunctional lacZ transcript was effected in cells by a PTM, which restored significant beta-galactosidase activity. These observations suggest that spliceosome-mediated RNA trans-splicing may represent a general approach for reprogramming the sequence of targeted transcripts, providing a novel approach to gene therapy.
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PMID:Spliceosome-mediated RNA trans-splicing as a tool for gene therapy. 1009 82

In vivo regulation of the LH receptor (LHR) promoter was studied using transgenic (TG) mice harboring fusion genes containing three different lengths of the LHR promoter (7.4 kb, 2.1 kb, and 173 bp), fused with coding sequence of the Escherichia coli beta-galactosidase (beta-GAL) reporter gene. The length of the LHR promoter significantly affected the pattern of beta-GAL expression. In the testis the shortest promoter directed expression primarily of the full-length beta-GAL mRNA, but mainly truncated messages were transcribed from the longer LHR promoter/beta-GAL constructs. The case was reversed in the ovary and adrenal gland. Furthermore, we have recently detected strong LHR expression in the adrenal gland of female mice with chronically elevated serum LH. Therefore, the regulation of the adrenal LHR expression was addressed in the present study using the LHR/beta-GAL TG mice. Elevated LH levels were achieved in the LHR/beta-GAL mice either by gonadectomy or cross-breeding them with TG mice overexpressing a chimeric protein of bovine LH beta-subunit and the C-terminal fragment of human chorionic gonadotropin-beta. In both models, beta-GAL mRNA was found in the adrenal cortex when the 7.4-kb LHR promoter was applied but not in mice carrying the 173-bp LHR promoter. The 7.4-kb construct was activated also in the ovaries in the double TG LHR(beta-GAL)/bovine LH beta-subunit/C-terminal fragment of human chorionic gonadotropin-betamice in some theca-interstitial cells surrounding the follicles. Hence, the LHR promoter elements essential for directing beta-GAL expression to the adrenal gland and ovary (7.4 kb) are different from those recently shown to be essential for the testicular expression (173 bp). In conclusion, elevated serum LH concentrations were found seminal for the LHR promoter activation in the ovaries and adrenals, and different lengths of the promoter are responsible for reporter gene expression in the testis, ovary, and adrenal gland.
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PMID:Transgenic mice harboring murine luteinizing hormone receptor promoter/beta-galactosidase fusion genes: different structural and hormonal requirements of expression in the testis, ovary, and adrenal gland. 1223 21

Primary cultures of progenitor and immature rat Leydig cells were established from the testes of 21- and 35-d-old rats, respectively. The cell population remained homogeneous after 4-6 d in culture as judged by staining for 3beta-hydroxysteroid dehydrogenase, but the cells were unable to bind 125I-human chorionic gonadotropin (hCG) or to respond to hCG with classical LH receptor (LHR)-mediated responses, including cAMP and inositol phosphate accumulation, steroid biosynthesis, or the phosphorylation of ERK1/2. Infection of primary cultures with recombinant adenovirus coding for beta-galactosidase showed that approximately 65% of the cells are infected. Infection with adenovirus coding for the human LHR (hLHR) allowed for expression of the hLHR at a density of approximately 25,000 receptors per cell and allowed the cells to respond to hCG with increases in cAMP and inositol phosphate accumulation, steroid biosynthesis, and the phosphorylation of ERK1/2. Although progenitor and immature cells were able to respond to hCG with an increase in progesterone, only the immature cells responded with an increase in testosterone. In addition to these classical LHR-mediated responses, the primary cultures of progenitor or immature rat Leydig cells expressing the recombinant hLHR proliferated robustly when incubated with hCG, and this proliferative response was sensitive to an inhibitor of ERK1/2 phosphorylation. These studies establish a novel experimental paradigm that can be used to study the proliferative response of Leydig cells to LH/CG. We conclude that activation of the LHR-provoked Leydig cell proliferation requires activation of the ERK1/2 cascade.
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PMID:Lutropin/choriogonadotropin stimulate the proliferation of primary cultures of rat Leydig cells through a pathway that involves activation of the extracellularly regulated kinase 1/2 cascade. 1741 5