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)

Four glycosidases (beta-galactosidase, alpha-mannosidase, alpha-fucosidase and beta-N-acetylglucosaminidase) were studied in chicken normal and regenerating liver, in turkey poult liver and in virus induced avian tumors--chicken hepatoma (strain Mc-29), Rous sarcoma (strain Schmidt-Ruppin) and turkey poult hemocytoblastoma nodules (strain Mc-31). The multiple forms of beta-N-acetylglucosaminidase were assayed as well. A particular enzyme pattern was found in the tumor lines under investigation. A characteristic property of hepatoma cells was the elevation of beta-galactosidase activity and of the former enzyme and that of beta-N-acetylglucosaminidase for the hemocytoblastoma. In Rous sarcoma the glycosidase activities (except that of alpha-fucosidase) were much lower, compared to the other two solid tumors. All enzyme activities were compared with those in the normal liver of the corresponding avian species, and with the liver of tumor bearing fowls and with regenerating chicken liver. Unlike the rat liver in the avian normal and tumor tissues the percentual ratio between the multiple forms A and B of beta-N-acetylglucosaminidase was found to be 30:70%.
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PMID:Glycosidases in normal and regenerating chicken liver, hepatoma Mc-29, Rous sarcoma, in turkey poult liver and hemocytoblastomes, provoked by the leukosis virus strain Mc-31. 298 24

Defective avian leukosis virus (ALV)-based vectors expressing the neo and LacZ genes were constructed under the control of cis-acting elements originated from 4 avian retroviruses: avian erythroblastosis virus (AEV), Rous associated viruses 1 (RAV-1) and 2 (RAV-2), and the Schmidt Ruppin strain of Rous sarcoma virus subgroup D (SR-RSV-D). We used these vectors to study the long-term stability of beta-galactosidase expression (encoded by the LacZ gene) in a permanent cell line from quail fibroblasts (QT6). Infection of the immortalized QT6 cell line with these vectors resulted in unstable beta-galactosidase expression. We determined whether this instability of provirus expression was correlated with: (1) presence of G418 selection; (2) deletion in the proviral genome; (3) hypermethylation of the proviral genome; (4) position of the neo and LacZ genes in the proviral genome; and (5) the transcriptional activity of the long terminal repeat (LTR) elements of proviral vectors. We observed that G418 selection pressure applied to infected QT6 cells lead to a more stable LacZ gene expression. Moreover, our results suggest a correlation between the stability of proviral gene expression and the level of gene expression driven by the LTR elements and depending on the strain origin of these.
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PMID:Influence of expression and cis-acting sequences from avian leukosis viruses (ALVs) on stability of (ALV)-based retrovirus vectors. 767 Oct

To analyze NF-kappa B activity in the testis, we used murine transgenic lines carrying a LacZ reporter gene under the control of a NF-kappa B-responsive promoter (Schmidt-Ullrich et al. [1996] Dev 122:2117-2128). We constructed three independent lines containing the promoter of the gene encoding p105, the precursor of the p50 subunit. This promoter contains three NF-kappa B-binding sites in its proximal part. Our results show that in adult mice, the beta-galactosidase activity which reflects nuclear NF-kappa B activity, is first detected in spermatocytes at the pachytene stage and remains activated in the following steps of germ cell differentiation and maturation. Using transgenic mice carrying a p105nlslacZ construct with the 3 NF-kappa B sites mutated in the p105 promoter, we found a significant reduction in the transgene activity, confirming the important role of NF-kappa B in the activation of the transgene. To confirm the stage of induction during spermatogenesis, we analysed the beta-galactosidase activity in the testes from prepuberal mice in which cells synchrouneously enter meiosis. We detected the transgene activity at 18 days after birth, corresponding to the pachytene stage in spermatocytes. In nuclear extracts prepared from prepuberal mice, we found a peak of NF-kappa B DNA-binding activity made of p50 and p65 subunits at day 18 after birth, which remains high in the later stages. Further analysis showed that I kappa B alpha and beta, but not epsilon are expressed in the testes. Altogether, these data suggest that NF-kappa B factors are stage specifically controlled and may play a role during the development of sperm cells.
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PMID:NF-kappa B is developmentally regulated during spermatogenesis in mice. 1106 90