Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gene UL41 of herpes simplex virus type 1 (HSV-1) and the corresponding gene of HSV-2, which control the virion-mediated early suppression of cellular protein synthesis, have been inactivated by inserting a beta-galactosidase expression cassette into their coding regions. The resulting recombinants grew well in tissue culture, although with the type 2 recombinant viral protein synthesis was slightly delayed. As a result of inactivation of UL41 host protein synthesis was not suppressed in the presence of actinomycin or early in normal infection, although it declined at a late stage. Polyribosomes were not broken down early in infection, cellular DNA synthesis was not inhibited and in the presence of cycloheximide stable alpha (immediate early) mRNA accumulated, in marked contrast to that of the parent HSV-2 strain. Comparison of the proteins of purified virions of HSV-1 and shutoff-defective recombinant virus revealed discrepancies consistent with the presence of the UL41 gene product in the enveloped virion.
...
PMID:Inactivation of the shutoff gene (UL41) of herpes simplex virus types 1 and 2. 217 88

Three mutants of herpes simplex virus type 1 (HSV-1) were used to deliver and express the Escherichia coli lacZ gene in cells of the rat central nervous system. Because the lacZ gene was inserted in place of the genes encoding one of the immediate-early viral proteins ICP0 or ICP4 or the early viral protein thymidine kinase, these mutants were compromised or defective in their ability to replicate. All mutant vectors exhibited reduced pathogenesis in animals as compared to the wild type HSV-1 strain KOS. In all cases lacZ was under the control of immediate-early or early viral promoters that are active in the early phase of infection. Expression of beta-galactosidase was observed in cortical neurons following stereotactic inoculation of mutant viruses into adult rat brains; distinct patterns of expression were observed with each mutant vector. Injection of the ICP0 mutant in the frontal cortex and caudate nucleus resulted in beta-galactosidase expression in a substantial number of cells around the inoculation site and at some distance from it for 14 days, with maximum expression after 3 days. The ICP0 vector appeared to have reached the ipsilateral and contralateral cingulate cortex by retrograde transport. Following inoculations of the ICP4 and thymidine kinase vectors into the same brain regions, only a few cells in areas immediately adjacent to the injection track expressed beta-galactosidase and they did so for only a few days. These herpes virus-derived vectors provide a means for the in situ delivery and expression of specific genes in neurons in the central nervous system with little adverse effect on animals.
...
PMID:Transfer and expression of the lacZ gene in rat brain neurons mediated by herpes simplex virus mutants. 217 4

Bovine herpesvirus 2 (BHV-2) specifies a glycoprotein of 130 kDa (gB BHV-2) which shows extensive homology to glycoprotein B (gB-1) of herpes simplex virus 1 (HSV-1). The BHV-2-specific 130-kDa glycoprotein is able to induce cross-reacting antibodies, some of which even cross-neutralize HSV-1. In order to determine the genome localization of gB BHV-2 and in order to identify conserved antigenic domains in both glycoproteins, we established libraries of subgenic fragments of BHV-2 and HSV-1 DNA in the prokaryotic expression vector lambda gt11 and screened them with cross-reacting monoclonal antibodies which allowed us to identify recombinant lambda gt11 clones expressing gB fusion protein. Nucleotide sequencing of inserted DNA fragments within these recombinant lambda gt11 clones revealed that they originated from the carboxy-terminal part of the major DNA-binding proteins (dbp) of BHV-2 (dbp BHV-2) and its counterpart ICP8 in HSV-1. Antisera raised against the beta-galactosidase fusion protein of recombinant phage lambda-113/2 coding for an 84 amino acid (aa) polypeptide originating from dbp BHV-2 neutralized infectivity of BHV-2 and HSV-1 in the presence of complement and precipitated [3H] glucosamine-labeled gB BHV-2 and gB-1. This antiserum also reacts with ICP8 and presumably with dbp BHV-2. Two hypotheses are discussed to explain this unexpected result: (i) epitopes in the carboxy-terminal part of gB BHV-2 and gB-1 are similar to antigenic determinants in the amino-terminal region of the gBs, thus providing cross-reacting antibody-binding sites; (iii) during gene expression a carboxy-terminal part of dbp BHV-2 and ICP8 genes might be spliced to the amino-terminal region of the glycoproteins gB BHV-2 and gB-1.
...
PMID:Common epitopes of glycoprotein B map within the major DNA-binding proteins of bovine herpesvirus type 2 (BHV-2) and herpes simplex virus type 1 (HSV-1). 245 78

The coding region for the major capsid protein (MCP) of human cytomegalovirus (HCMV) was identified by comparing the protein sequence with the respective sequences of herpes simplex virus (HSV), Epstein-Barr virus, and varicella-zoster virus. The predicted length of the HCMV MCP was 1,370 amino acids. Comparison of the MCP sequences of the different human herpesviruses showed a homology of 25% to the MCP of HSV type 1, a homology of 29% to the MCP of Epstein-Barr virus, and a homology of 23% to the MCP of varicella-zoster virus. A subfragment of the HSV type 1 KpnI i fragment encoding the MCP VP5 cross-hybridized with the HCMV HindIII U fragment containing part of the MCP gene. Northern (RNA) blot analyses with subclones out of the coding region for the HCMV MCP detected one large transcript of about 8 kilobases. A portion of the open reading frame was expressed in Escherichia coli plasmid pBD2 IC2OH as a beta-galactosidase fusion protein and was used to generate polyclonal antibodies in New Zealand White rabbits. The obtained antisera reacted in Western immunoblots with the MCP of purified HCMV virions. A monoclonal antibody against the human MCP and a monospecific rabbit antiserum against strain Colburn of simian cytomegalovirus detected the fusion protein as well as the MCP of purified virions in immunoblots.
...
PMID:Identification of the major capsid protein gene of human cytomegalovirus. 253 37

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.
...
PMID:Decreased messenger RNA translation in herpesvirus-infected arterial cells: effects on cholesteryl ester hydrolase. 254 44

During latent infection by herpes simplex virus (HSV), an abundant latency-associated transcript (LAT) that is antisense to a predominant viral alpha gene (ICP0) is found localized in the nucleus of sensory neurons. We disrupted both copies of the LAT gene in the HSV-1 genome by insertion of the Escherichia coli lacZ gene under LAT promoter control. The resulting recombinant virus, RH142, does not express any detectable LAT in either latently or productively infected cells, although beta-galactosidase expression is readily detectable in sensory neurons of latently infected mice. Expression was first detectable 3 days postinoculation and continued at approximately the same level for the entire experimental period (56 days). beta-Galactosidase expression was not detectable at any time during RH142 replication in Vero cells. Thus, the kinetics of expression and cell-type specificity of the LAT gene are distinct from other HSV-1 genes that are expressed during productive growth. When latently infected trigeminal ganglia were explanted, RH142 reactivated from latency with the kinetics and an efficiency indistinguishable from the parental wild-type virus. These studies argue against any possible antisense regulatory mechanism of LAT in the regulation of viral gene expression or any role of LAT-encoded protein during the establishment or maintenance of latency in the mouse.
...
PMID:Herpes simplex virus latent RNA (LAT) is not required for latent infection in the mouse. 255 49

We have isolated several mutant herpes simplex viruses, specifically mutated in the infected cell protein 8 (ICP8) gene, to define the functional domains of ICP8, the major viral DNA-binding protein. To facilitate the isolation of these mutants, we first isolated a mutant virus, HD-2, with the lacZ gene fused to the ICP8 gene so that an ICP8-beta-galactosidase fusion protein was expressed. This virus formed blue plaques on ICP8-expressing cell lines in the presence of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside. Mutated ICP8 gene plasmids cotransfected with HD-2 DNA yielded recombinant viruses with the mutant ICP8 gene incorporated into the viral genome. These recombinants were identified by formation of white plaques. Four classes of mutants were defined: (i) some expressed ICP8 that could bind to DNA but could not localize to the cell nucleus; (ii) some expressed ICP8 that did not bind to DNA but localized to the nucleus; (iii) some expressed ICP8 that neither bound to DNA nor localized to the nucleus; and (iv) one expressed ICP8 that localized to the cell nucleus and bound to DNA in vitro, but the mutant virus did not replicate its DNA. These classes of mutants provide genetic evidence that DNA binding and nuclear localization are distinct functions of ICP8 and that ICP8 has nuclear functions other than binding to DNA. Furthermore, the portion of ICP8 needed for a nuclear function(s) distinct from DNA binding is the part of ICP8 showing sequence similarity to that of the cellular protein cyclin or proliferating cell nuclear antigen.
...
PMID:Genetic evidence for multiple nuclear functions of the herpes simplex virus ICP8 DNA-binding protein. 255 53

A novel amplification system has been developed for the detection of free or antibody-conjugated alkaline phosphatase. The amplification system provides a 100 fold enhancement in the detection of the enzyme, compared to direct detection with chromogenic substrates. The key to the amplification system is the dephosphorylation of a potent phosphorylated inhibitor, and the visualization of this inhibitor using a second, indicator, reaction. This system is shown to provide increased sensitivity for immunoassays detecting either herpes simplex virus or respiratory syncytial virus in clinical samples. In addition, this general concept for amplification may be applicable to a variety of other hydrolytic enzymes, and is demonstrated for the enhanced detection of beta-galactosidase.
...
PMID:The development of a novel immunoassay amplification system and its use in viral detection. 255 98

This report describes a novel system for the immunological detection of immobilized antigen. The detection of herpes simplex virus (HSV) antigen was used as an example. Bacteriophage M13, containing the E. coli lac Z gene, was used as the "reporter" molecule in an immunoassay which is otherwise analogous to the enzyme-linked immunoabsorbant assay (ELISA). Briefly, HSV infected cells were incubated with a mouse monoclonal antibody specific for HSV antigen, followed by rabbit anti-mouse serum and mouse anti-M13 serum. Immune complexes were incubated with viable M13 phage. M13 binding was due to the presence of M13 antibodies, whose presence ultimately depended on the binding of monoclonal antibody to HSV. Phage was recovered by elution in pH = 11. Recovered phage was used to infect E. coli. M13 was quantitated by either plaque assay or by an assay for phage-induced beta-galactosidase activity in appropriate E. coli strains. The amount of M13 recovered was proportional to the number of HSV infected cells probed. Therefore, M13 served as a "bio-amplifiable tag" to antibody, as enzymes do in the ELISA. Since M13 is viable, its signal can be amplified by infection of susceptible bacteria, and the promise for an enormously sensitive immunoassay exists. The sensitivity of the assay described here is compared to the ELISA in the detection of HSV infection cells, as an example of the novel assay's potential. Significantly, the novel assay was more sensitive than the ELISA when samples were tested under identical circumstances. This technique is called the phage-linked immunoabsorbant assay (PHALISA), by analogy to the ELISA.
...
PMID:A phage-linked immunoabsorbant system for the detection of pathologically relevant antigens. 256 Oct 61

Herpes simplex virus (HSV) encodes a ribonucleotide reductase consisting of two subunits (140 and 38 kilodaltons) whose genes map to coordinates 0.56 to 0.60 on the viral genome. Host cell lines containing the HpaI F fragment which includes the reductase subunit genes of HSV type 1 strain KOS (coordinates 0.535 to 0.620) were generated. Transfection of these cells with a plasmid containing the immediate-early ICP0 gene resulted in the expression of ICP6; interestingly, ICP4 plasmids failed to induce expression, indicating an unusual pattern of ICP6 regulation. One such cell line (D14) was used to isolate a mutant with the structural gene of lacZ inserted into the ICP6 gene such that the lacZ gene is read in frame with the N-terminal region of ICP6. This mutant generated a protein containing 434 amino acids (38%) of the N terminus of ICP6 fused to beta-galactosidase under control of the endogenous ICP6 promoter. Screening for virus recombinants was greatly facilitated by staining virus plaques with 5-bromo-4-chloro-3-indoyl-beta-D-galactoside (X-gal). Enzyme assays of infected BHK cells indicated that the mutant is incapable of inducing viral ribonucleotide reductase activity. Surprisingly, although plaque size was greatly reduced, mutant virus yield was reduced only four- to fivefold compared with that of the wild type grown in exponentially growing Vero cells. Mutant virus plaque size, yields, and ability to synthesize viral DNA were more severely compromised in serum-starved cells as compared with the wild type grown under the same condition. Although our evidence suggests that the HSV type 1 ribonucleotide reductase is not required for virus growth and DNA replication in dividing cells, it may be required for growth in nondividing cells.
...
PMID:Herpes simplex virus type 1-induced ribonucleotide reductase activity is dispensable for virus growth and DNA synthesis: isolation and characterization of an ICP6 lacZ insertion mutant. 282 47


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---