Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: KEGG:D03345 (beta-Galactosidase)
 434 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The proximal 5'-flanking region of the alpha-subunit gene from humans and cattle confers pituitary-specific expression to heterologous reporter genes in transgenic mice. To investigate whether these promoter regions also contain the necessary regulatory elements for cell-specific expression and hormonal regulation, we used three independent lines of transgenic mice. Two lines of transgenic mice contained chimeric genes consisting of either 1.6 kilobasepairs (kbp) of human or 3 15 basepairs of bovine alpha-subunit proximal 5'-flanking sequence linked to the bacterial gene encoding chloramphenicol acetyltransferase (CAT). A third line of transgenic mice contained the proximal 1.6 kbp of 5'-flanking sequence of the human alpha-subunit gene linked to the bacterial lacZ gene encoding beta-galactosidase (beta gal; H alpha beta gal transgenic mice). Hormonal replacement paradigms indicate that both human and bovine alpha CAT transgenes are regulated by GnRH, suggesting that their expression occurs in gonadotropes. Thus, the proximal 5'-flanking regions of both the human and bovine alpha-subunit genes must contain regulatory elements that confer both gonadotrope-specific expression and responsiveness to GnRH. In contrast to the human alpha-subunit promoter, the bovine alpha-subunit promoter lacks a functional cAMP response element, suggesting that transduction of both cell-specific and GnRH transcriptional signals occurs through cAMP response element-independent pathways. Thyrotropes also express the glycoprotein hormone alpha-subunit gene. Yet, hormone replacement paradigms with propylthiouracil and T3 were ineffective in altering CAT activity in the pituitary of human or bovine alpha CAT transgenic mice. Because a thyroid hormone response element has been localized to the proximal 5'-flanking region of the human alpha-subunit gene, these data suggest that the alpha CAT transgenes lack sufficient information to direct expression to thyrotropes. Direct evidence for this possibility was obtained through immunocytochemical studies performed on pituitaries from H alpha beta gal transgenic mice. beta-Galactosidase activity appeared in gonadotropes, but not thyrotropes. We conclude, therefore, that distinct and separable regulatory elements mediate the expression of the alpha-subunit gene in gonadotropes and thyrotropes.
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PMID:Gonadotrope- and thyrotrope-specific expression of the human and bovine glycoprotein hormone alpha-subunit genes is regulated by distinct cis-acting elements. 128 Mar 29

Human Fibroblast Activation Protein (FAP), a member of the serine prolyl oligopeptidase family, is a type II cell surface glycoprotein that acts as a dual-specificity dipeptidyl-peptidase (DPP) and collagenase in vitro. Its restricted expression pattern in embryonic mesenchyme, in wound healing and in reactive stromal fibroblasts of epithelial cancers, has suggested a role for the FAP protease in extracellular matrix degradation or growth factor activation in sites of tissue remodeling. The FAP homologue in Xenopus laevis has been reported to be induced in the thyroid hormone-induced tail resorption program during tadpole metamorphosis supporting a role for FAP in tissue remodeling processes during embryonic development. However, Fap-deficient mice show no overt developmental defects and are viable. To study the expression of FAP during mouse embryogenesis, a second Fap-deficient mouse strain expressing beta-Galactosidase under the control of the Fap promoter was generated by homologous recombination (Fap-/- lacZ mice). FAP deficiency was confirmed by the absence of FAP-specific dipeptidyl-peptidase activity in detergent-soluble extracts isolated from 17.5 d.p.c. Fap-/- lacZ embryos. We report that Fap-/- lacZ mice express beta-Galactosidase at regions of active tissue remodeling during embryogenesis including somites and perichondrial mesenchyme from cartilage primordia.
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PMID:Expression of the fibroblast activation protein during mouse embryo development. 1133 Aug 65

The impact of hyperthyroidism on epididymal glycosidases was studied in albino rats. Hyperthyroidism was induced in Wistar rats aged 30 days by daily injection of T4 (25 microg/100 g body weight/day intramuscularly) for 30 or 60 days; control rats were injected with vehicle (alkaline saline, pH 7.8). One set of hyperthyroid rats was reverted to euthyroid status by withdrawing T4 treatment after 30 days of hyperthyroidism. To asses the direct effect of thyroid hormone on epididymal hexosaminidases, caput, corpus and cauda tissues were stimulated with 25, 50 or 100 ng/mL T3 for 24 h, after an initial culture of 24 h. The activity of beta-glucosidase decreased in caput, corpus and cauda epididymis of hyperthyroid rats. beta-Galactosidase activity increased in the caput epididymis irrespective of the duration of hyperthyroidism. While a similar decrease occurred in the corpus and cauda epididymis in the 30 day hyperthyroid group, an opposite trend was observed in 60 day hyperthyroid rats. Caput beta-N-acetylglucosaminidase activities increased at both time points, whereas activity decreased in the corpus and cauda in 30 day, but increased in 60 day hyperthyroid rats. Hyperthyroidism consistently increased caput and corpus beta-N-acetylgalactosaminidase activity irrespective of the duration. Cauda epididymal beta-N-acetylgalactosaminidase activity was decreased in 30 day and increased in 60 day hyperthyroid rats. Hyperthyroidism induced changes in caput beta-galactosidase, beta-N-acetylgalactosaminidases, corpus beta-N-acetylglucosaminidase and cauda beta-N-acetylgalactosaminidase which were irreversible while the remaining actvities were brought back to normal when T4 treatment was withdrawn. In vitro studies showed that T3 stimulates epididymal hexosaminidases (beta-N-acetylglucosaminidase and beta-N-acetylgalactosaminidase) irrespective of the dose. These data suggest that thyroid hormones have a specific and direct influence on glycosidases in specific regions of the epididymis.
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PMID:Differential effect of hyperthyroidism on rat epididymal glycosidases. 1145 72