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)

Introducing genes into adult neurons in vivo may be a useful experimental tool for studying and modifying neuronal function. In this study two herpes simplex virus type 1 (HSV-1) mutants were used to examine the capability of different types of neostriatal neurons to express a foreign gene introduced through viral infection. In these HSV-1 mutants (7134 and RH105) the Escherichia coli gene, lacZ, under the control of viral promoters active during the early phase of infection, was substituted for viral genes (ICPO and TK, respectively) needed for efficient replication in the nervous system. Adult male rats received unilateral injections of HSV-1 mutant 7134 or RH105 into the neostriatum. Animals survived for 1 to 70 days with no apparent adverse physiological or behavioral effects. At the injection site, both mutant viruses produced focal tissue necrosis and reactive gliosis. Histochemical detection of the lacZ gene product, beta-galactosidase (beta Gal), revealed extensive labeling of neurons with mutant 7134 and relatively limited neuronal labeling with the mutant RH105. Mutant 7134, which is capable of some replication in cells, conferred beta Gal expression in cells over an area that was twofold greater than the necrotic area. In contrast, mutant RH105, which cannot replicate in cells, produced a zone of beta Gal-labeled cells only two-thirds the area of the necrotic core. Both medium- and large-sized neostriatal neurons were positive for beta Gal, and a higher proportion of large cells were labeled as compared to other neuronal populations in the normal striatum. A few glial cells were also beta Gal-positive. Retrograde transport of virus to the substantia nigra pars compacta and to the cortex was minimal and occurred only with mutant 7134. No evidence was seen for anterograde transport. Immunohistochemical localization of beta Gal at the ultrastructural level after inoculation with mutant 7134 revealed that both types of medium-sized neurons (spiny and aspiny types), as well as large neurons, were infected 3 days following inoculation. Immunoreactive neurons ranged from severely pathologic to remarkably healthy. Some of the axon terminals that contacted beta Gal-immunoreactive dendrites and spines were degenerated. These results demonstrate that in the adult rat replication-deficient HSV-1 vectors injected intrastriatally can be used to express a foreign gene in at least three types of neostriatal neurons, while maintaining the long-term survival and general health of the injected animals. The neurotoxicity induced by HSV-1 mutants may still be considerable, however, and ways of minimizing neuropathological effects need to be addressed.
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PMID:Introduction of a foreign gene (Escherichia coli lacZ) into rat neostriatal neurons using herpes simplex virus mutants: a light and electron microscopic study. 131 Dec 66

The infection of cells by vesicular stomatitis virus results in the rapid inhibition of host-cell protein synthesis, but not of viral protein synthesis. To determine if this translational selectivity might be conferred by the viral mRNA, we constructed a plasmid (pUCLN beta-4) containing the 5' end of the viral nucleocapsid (N)-gene, including the ribosome binding site, fused in frame with the gene encoding beta-galactosidase, and compared it to a control plasmid (pMC1924) containing the cellular rabbit beta-globin gene 5' end fused with the beta-galactosidase encoding gene. Both plasmids contained identical promoter and 3' nontranslated regions and expressed similar levels of beta-galactosidase in the indicator cell line 293. In cells transfected with either plasmid, viral infection resulted in a approximately 70% decrease in protein synthesis by five hours. The level of beta-galactosidase from cells transfected with pMC1924 also decreased concomitantly with the decrease in total protein synthesis. However, the level of beta-galactosidase from cells transfected with pUCLN beta-4 was not affected by viral infection. Our data suggest that sequences in the 5' end of the viral mRNA allow for the selective translation of the viral message in the presence of an inhibited translational machinery.
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PMID:5' sequence of vesicular stomatitis virus N-gene confers selective translation of mRNA. 133 74

It is poorly understood why vaccines could not be developed for the control and prevention of African swine fever (ASF) virus infection. The aim of our study was to identify genes non-essential for ASF virus replication because there were indications that certain viral gene products, which apparently are non-essential for viral replication, conferred protection from death due to ASF. A cosmid library representing the genome of ASF virus strain France 64 was established and characterized. Then, in order to inactivate viral genes by insertion, the beta-galactosidase (beta-gal) gene was introduced either randomly or at specific locations of selected cloned DNA fragments. These constructions were transfected into cells which had been previously infected with a cell-culture-adapted viral strain in order to allow the generation of recombinant progeny virus. Viable recombinant progeny was identified by at least one of the following means: (1) expression of beta-gal; (2) detection of beta-gal specific DNA by plaque hybridization, and (3) absence of a functional product of the inactivated gene. Presently, we are characterizing a recombinant virus with an insertionally inactivated thymidine kinase gene.
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PMID:Approaches to the identification of non-essential genes of African swine fever virus. 148 51

Homologous recombination is shown to be specifically induced in Vero cells by infection with African swine fever (ASF) virus. The frequency of recombination induced by ASF virus infection between cotransfecting plasmids is comparable to that found after infection with the prototype poxvirus, vaccinia virus. The induction of recombination is accompanied by replication of the plasmid templates in the ASF virus-infected cells. An ASF virus insertion/expression plasmid vector containing the Escherichia coli reporter gene beta-galactosidase (beta-gal) fused to a viral promoter sequence was constructed. Recombination between homologous sequences present in both the plasmid vector and the virus genome led to the generation of recombinant viruses expressing the beta-gal gene. Visual screening of beta-gal+ plaques allowed the isolation and plaque purification of recombinant ASF viruses. The characterization of a beta-gal+ virus isolate showed that the beta-gal gene had been stably inserted into the thymidine kinase locus of the virus genome, thus demonstrating that controlled genetic manipulation of ASF virus can be achieved by homologous recombination in infected cells.
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PMID:Genetic manipulation of African swine fever virus: construction of recombinant viruses expressing the beta-galactosidase gene. 156 85

A quantitative bioassay for human immunodeficiency viruses has been developed on the basis of the ability of the tat gene to transactivate the expression of an integrated beta-galactosidase gene in a HeLa-CD4+ cell line. Infection by a single virion of HIV-1 or HIV-2 corresponds to a unique blue syncytium or a cell cluster detected after fixation and addition of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (a beta-galactosidase substrate). The number of infected lymphoid cells in a culture (stimulated human peripheral blood lymphocytes and cell lines) can also be quantified by cell-to-cell transmission of HIV into the HeLa-CD4(+)-beta-galactosidase monolayer. Infections by simian immunodeficiency viruses are similarly detected. This assay has been used to determine the dose response of drugs, the half-life of HIV at 37 degrees C, and the appearance of infectious particles after virus infection.
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PMID:Activation of a beta-galactosidase recombinant provirus: application to titration of human immunodeficiency virus (HIV) and HIV-infected cells. 211 May 96

The baculovirus Autographa californica nuclear polyhedrosis virus (AcMNPV, which is representative of the MNPV subtype in which the virions may contain many nucleocapsids within a single viral envelope) encodes a protein, v-ubi, that has 76% identity with the eukaryotic protein ubiquitin. Transcriptional mapping indicated that the gene for v-ubi was transcribed during the late phase of viral infection. Two transcriptional start sites potentially encoding v-ubi were identified. Both sites were contained within a sequence motif common to baculovirus late genes. A recombinant virus, AcUbi-beta Gal, encoding a ubiquitin-beta-galactosidase fusion protein was constructed to monitor the temporal regulation of v-ubi gene during viral infection. The fusion protein was expressed maximally at 14-18 hr postinfection, consistent with its classification as a late protein. The amount of ubiquitin-beta-galactosidase fusion protein that accumulated in AcUbi-beta Gal-infected cells by 48 hr postinfection was approximately 14% of the level of beta-galactosidase that was synthesized under control of the polyhedrin promoter. Transcriptional analysis confirmed that synthesis of the fusion protein was directed by the v-ubi gene promoter. AcUbi-beta Gal also produced normal levels of authentic viral ubiquitin message. Southern blot analysis of AcUbi-beta Gal and 15 additional isolates revealed that the fusion sequences had not recombined at the ubiquitin locus. A polyubiquitin gene was isolated and sequenced from Spodoptera frugiperda, a lepidopteran host cell line for AcMNPV. The predicted amino acid sequence of the product of the host gene is identical to animal ubiquitin.
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PMID:Identification of a viral gene encoding a ubiquitin-like protein. 215

Membrane receptors for rubella virus (RV) in Vero cells were studied by means of two different approaches: (i) by enzyme treatment of the whole cell membrane and (ii) by testing the ability of isolated plasma membrane molecules to compete with cells for virus binding. The replication of RV was studied with both indirect immunofluorescence assay and molecular hybridization techniques. Phospholipases A2 and C digestion of cells greatly reduced the infectivity by the virus, pointing towards the involvement of lipid structures as receptor sites for RV. Furthermore, susceptibility of Vero cells to virus infection was also reduced after beta-N-acetyl-D-glucosaminidase, alpha-glucosidase and beta-galactosidase treatment, suggesting that carbohydrate residues may participate in a complex cellular receptor structure for RV. When the major membrane lipids were examined separately for their ability to inhibit viral infectivity, several phospholipids (phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine, sphingomyelin) and glycolipids (gangliosides, lactosylceramide, cerebroside sulphate) showed a strong neutralizing activity, confirming the role of membrane lipid moiety in the cell surface receptor for RV.
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PMID:Role of membrane phospholipids and glycolipids in the Vero cell surface receptor for rubella virus. 219 46

SV40 virus infection is able to induce tumours in newborn hamsters and to transform a wide range of eukaryotic cells in in vitro culture. This is achieved by integration of the viral DNA into the host cell DNA and expression of the virus-encoded Large T-antigen. The expression of Large T, a 708 amino acid phosphoprotein, is required both to induce and maintain the transformed state. The Large T protein initiates viral DNA synthesis and regulates viral transcription, apparently by binding in a specific manner to viral DNA sequences at and near the viral origin of replication. SV40 Large T also affects cellular DNA synthesis and transcription and this may account for its oncogenic activity. A novel immunochemical procedure has permitted the isolation of cellular DNA sequences occupied by SV40 Large T in the chromatin of SV40 transformed cells. Some of the cellular sequences contain high affinity binding sites for SV40 Large T, and hybridize to messenger RNAs expressed in SV40 transformed but not in normal cells. A second type of cellular target for Large T is the cell coded p53 protein that it binds to and stabilizes. A range of monoclonal antibodies to p53 has been isolated and characterized. They demonstrate that p53 is in the cytoplasm of normal cells but is located in the nucleus of transformed cells. One of the antibodies recognizes an epitope on p53 that is stabilized or induced by binding to Large T. Further studies on the T-p53 protein complex have been facilitated by constructing bacterial plasmids that direct the synthesis of substantial quantities of Large T-beta-galactosidase and p53-beta-galactosidase fusion proteins in bacteria. The results are discussed in the context of our current knowledge of oncogene action.
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PMID:Cellular targets for SV40 large T-antigen. 241 84

Herpes simplex viruses (HSVs) contain a function that can cause the degradation of host mRNA and mediate the shutoff of host protein synthesis. Previously, we observed that HSV infection causes a 40-fold increase in cholesteryl ester (CE) accretion in arterial smooth muscle cells due, in part, to a substantial decrease in CE hydrolysis. In studies reported herein, we found that HSV infection leads to reduced immunoprecipitable lysosomal (acid) CE hydrolase (ACEH) and beta-galactosidase, another lysosomal enzyme in vascular smooth muscle cells. The HSV-induced reduction was greater with respect to ACEH than beta-galactosidase. To determine whether degradation of host cellular mRNA or inhibition of cellular translation was responsible for decreased CE hydrolysis in HSV-infected smooth muscle cells, we utilized an in vitro translation system that permitted us to compensate for any mRNA degradation during viral infection. Reduced ACEH activity was observed in the total cellular RNA translation products of HSV-infected smooth muscle cells compared to uninfected cells owing to posttranscriptional modification. We conclude that the decrease in CE hydrolysis in HSV-infected smooth muscle cells is caused primarily by decreased ACEH synthesis and activity, which can contribute to CE accretion in these vascular cells.
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PMID:Decreased messenger RNA translation in herpesvirus-infected arterial cells: effects on cholesteryl ester hydrolase. 254 44

Oligopeptides of the highly conserved herpes virus glycoprotein B (gB) were expressed from DNA fragments of the EBV gB (BALF4) and HSV-2 gB open reading frames as fusion proteins with the lambda CII protein and beta-galactosidase (GZ), respectively, in Escherichia coli. After immunopurification using anti-gB or anti-GZ affinity columns, the fusion proteins were used in vitro to stimulate human peripheral blood lymphocytes (PBL) or murine lymph node cells that have been primed with EBV, HSV-1, HSV-2, VZV or HCMV (all human herpes viruses) to proliferate. Results obtained in BALB/c mice indicate that different herpes viruses induce different levels of T-cell response to each other and to gB, over a range of type-specific and cross-reactive T-cell epitopes. There is a lack of correlation of immunogenicity and antigenicity in the generation of T-cell responses between some of the viruses. Major T-cell epitopes are located at the C terminal half of the gB molecule. The T-cell response to gB in healthy individuals seropositive for various combinations of the five herpes viruses differed markedly from individual to individual, even when they are seropositive to the same set of herpes viruses. However, two individuals with high proliferative T-cell response to VZV and sharing HLA A2, B7, DR2 and DQw1 are also good responders for cross-reactive gB/fragments and for virus antigen of all the five herpes viruses. Therefore the data obtained demonstrated that the MHC and the immune interaction arising from cross-reactive T-cell response evoked by other herpes viruses may determine the pathogenesis of a herpes virus infection.
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PMID:Proliferative T-cell response to glycoprotein B of the human herpes viruses: the influence of MHC and sequence of infection on the pattern of cross-reactivity. 255 84


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