PMID(sorted ascending)
purification and properties of a virion protein kinase.the protein kinase associated with virions of frog virus 3 was purified to apparent homogeneity by ion exchange chromatography and gel filtration. the enzyme protein appeared as a single polypeptide of molecular weight 50,000 to 55,000 as determined by gel filtration, glycerol gradient sedimentation, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and comprised approximately 0.4% of the total virion protein. the activity was classified as a cyclic nucleotide-independent protein ki ...19765456
fibrillar bodies in hepatocyte nuclei during the course of the toxic hepatitis produced by frog virus 3 in mice. 1975163907
inhibition of vesicular stomatitis virus replication by frog virus 3. selective action on secondary transcription. 1978213882
the inhibition of vesicular stomatitis virus protein synthesis by frog virus 3. 1979220794
[protection of mice with bacterial phospholipids against the lethal effect of frog virus 3 (fv 3) (author's transl)].a bacterial phospholipid extract (ebp) inoculated intraveinously at a dose of 1 mg/25 g body weight 30 hours before infection protects mice against the lethal effect of frog virus 3 (fv 3). the anti-fv 3 resistance produced by ebp requires protein synthesis during the period of pretreatment. the treatment with the bacterial extract has no effect on the inhibition of the macromolecular synthesis of the liver (rna and dna) which is observed at the beginning of the infection. however 48 hours after ...1979388298
multiplication of vaccina virus in the livers of mice after frog virus 3-induced damage to sinusoidal cells. 1979390146
macromolecular synthesis in cells infected by frog virus 3. x. inhibition of cellular protein synthesis by heat-inactivated virus. 1979506065
macromolecular synthesis in cells infected by frog virus 3. xi. a ts mutant of frog virus 3 that is defective in late transcription. 1979506066
nongenetic reactivation of frog virus 3 dna. 1979506069
a low resolution structure of frog virus 3. 1979516448
macromolecular synthesis in cells infected by frog virus 3. vi. frog virus 3 replication is dependent on the cell nucleus.previous evidence indicated that frog virus 3 (fv3), an icosahedral dna virus, replicates exclusively in the cytoplasm. however, data presented here demonstrate that fv3 does not replicate in uv-irradiated or enuleated chicken embryo or bsc-1 cells and that virus-specific dna synthesis is not initiated in such cells. primary transcription was not detected in infected enucleated cells. these results demonstrate that a functional nucleus is essential for fv3 replication.1977556785
macromolecular synthesis in cells infected by frog virus 3. vii. transcriptional and post-transcriptional regulation of virus gene expression.we have used improved techniques for separating individual species of rna and protein to study the mechanisms that control gene expression by frog virus 3, a eucaryotic dna virus. forty-seven species of viral rna and 35 viral polypeptide species were resolved by polyacrylamide gel electrophoresis. the relative molar ratios of virus-specific polypeptides synthesized at various times after infection were determined by computer planimetry and were compared with the molar ratios of appropriate-sized ...1977561861
frog virus 3 morphogenesis: effect of temperature and metabolic inhibitors.the different stages of frog virus 3 (fv 3) morphogenesis have been investigated in chick embryo fibroblasts infected at an optimal temperature for virus growth (29 degrees c). the metabolic requirements for morphogenesis were determined by adding inhibitors of macromolecular synthesis at different periods in the virus growth cycle. the effect of a non-permissive temperature for fv 3 replication (37 degrees c) was also studied in shift up experiments. the following results were obtained: (i) whe ...1977562390
macromolecular synthesis in cells infected by frog virus 3. ix. two temporal classes of early viral rna. 1978566482
macromolecular synthesis in cells infected by frog virus 3. xii. viral regulatory proteins in transcriptional and post-transcriptional controls.using fluorophenylalanine (fpa) to interfere with functional viral protein synthesis, we have investigated the complex transcriptional and post-transcriptional controls that operate in cells infected with frog virus 3. our previous data, obtained by polyacrylamide gel electrophoresis of viral rnas and proteins, showed that the addition of fpa at the beginning of infection completely prevented the synthesis of late viral rnas and late viral proteins and blocked the normal progressive decline in t ...1979574166
[effect of a water-soluble derivative of silymarin on morphological and functional alterations of mouse hepatocytes induced by frog virus 3 (author's transl)].pretreatment of mice with silymarin dihemisuccinate sodium salt (shs-na) 300 mg/kg 24 and 16 h before infection completely protected against the lethal effect of frog virus 3 (fv3). after the inoculation of 1 ld100 of virus it could be shown that: a) the same amount of radioactively labelled virus was found in the liver of control and shs-na treated animals, b) in shs-na pretreated animals the shut-off of macromolecular syntheses in the liver was considerably less extensive, c) the histological ...1979582977
[sinusoidal cells of the liver in toxic hepatitis induced by the fv3 (frog virus 3): ultrastructural changes in kupffer cells and endothelial cells]. 1977609297
[sinusoidal cells of the liver in toxic hepatitis induced by the fv3 (frog virus 3): functional repercussions of morphological changes]. 1977609298
macromolecular synthesis in cells infected by frog virus 3. viii. the nucleus is a site of frog virus 3 dna and rna synthesis. 1978619492
phagocytic properties displayed by mouse hepatocytes after virus induced damage of the sinusoidal lining.frog virus 3 (fv 3) inoculated intravenously into mice damages sinusoidal cells and produces a decrease in the carbon uptake capacity of the liver. histological and ultrastructural examinations have shown that in fv 3 infected animals part of the inoculated carbon is taken up by the hepatocytes and can be located inside cytoplasmic vesicles or dense bodies. the hepatocytes are also able to phagocyte latex particles of 312 nm in diameter. these observations demonstrate that once the kupffer cells ...1978667283
budding of frog virus 3 (fv3) studied by means of sequential immunocytochemical labeling. 1976785020
hepatocellular necrosis during frog virus 3-induced hepatitis of mice: an electron microscopic study. 1977885221
cell killing by frog virus 3: evidence for cell killing by single viral particles or single viral subunits. 1977921788
macromolecular synthesis in cells infected by frog virus 3. iv. regulation of virus-specific rna synthesis. 1976944493
macromolecular synthesis in cells infected with frog virus 3. v. the absence of polyadenylic acid in the majority of frog virus 3-specific mrna species. 1976960576
effect of non-permissive temperature on protein synthesis of frog virus 3 infected the present paper we describe the kinetics of virus specific protein synthesis in fv3-infected bhk cells incubated at the non-permissive temperature of 33 degrees c. some quantitative differences were detected, in comparison with proteins synthesized at permissive temperature (26 degrees c). thereafter we studied the fate of polypeptides pulse labelled at non-permissive temperature, by shifting the infected cells to permissive temperature. in such experimental conditions infectious virus is r ...19761016578
[a novel model of experimental toxic hepatitis/acute degenerative hepatitis induced by frog virus 3 (fv3) in the mouse (author's transl)].the i.p. or i.v. injection of frog virus 3 (fv3) in mice produces a hepatitis which leads to the death of the animals within 24 h. this hepatitis is of a purely toxic nature since the virus does not develop at 37 degrees c. the toxic effect of the virus, which can be differentiated from the infectious effect, involves one or more structural proteins. the first pathological changes occur during the first few hours after the injection in the vicinity of the nuclei of the liver parenchyma cells in ...19751081877
arginine requirement for frog virus 3 development. 19751167719
effects on host cell polyribosomes following infection with frog virus 3 at a non-permissive temperature. brief report. 19751168042
frog virus 3 replication: electron microscope observations on the sequence of infection in chick embryo fibroblasts.the replication of frog virus 3 in primary chick embryo fibroblasts has been studied by examination of thin sections with the electron microscope and the assay of infectious viurs. uptake of frog virus 3 by the cells was observed to occur by pinocytosis and this may be the method of entry. early in infection (i h p.i.) marked margination of the nuclear chromatin occurred and the chromatin remained in this condition throughtout the infection. foci of infection were first detected in the cytoplasm ...19751168241
modifications of cellular rna-polymerase ii after infection with frog virus 3.rna-polymerase ii extracted from fv3-infected and uninfected bhk cells were compared by measuring their abilities to bind [3-h]-amanitin and ribonucleoside triphosphates. binding sites for [3-h]-amanitin and the dissociation constant of the complex between [3h]-amanitin and rna-polymerase ii were significantly modified following fv3 infection. the apparent km's for ribonucleoside triphosphates remained unchanged.19751170279
macromolecular synthesis in cells infected with frog virus 3. iii. virus-specific protein synthesis by temperature-sensitive mutants. 19751171552
[hyperammonemia and hypoglycemia in acute degenerative hepatitis induced in mice by frog virus 3]. 19751219252
localization of polypeptides in frog virus 3 by radioiodination technique.frog virus 3 is an amphibian icosahedral deoxyribovirus which replicates in the cytoplasm of infected cells. the radioiodination of purified virions using the enzyme lactoperoxidase has shown that the major component of the structural proteins is only partially exposed through the lipoprotein membrane that constitutes the outer layer of the icosahedral capsid.19751230060
frog virus 3 replication: electron microscope observations on the terminal stages of infection in chronically infected cell examination of bhk, cef, and fhm cells chronically infected with frog virus 3 has been made by scanning and transmission (thin section, freeze fracture, and surface replica) electron microscopy. with minor differences the pattern of virus development is similar in all three cell line. virus particles were detected in cell nuclei which subsequently became degenerate very late in infection. three inclusions were associated with frog virus 3 cytoplasmic foci of infection; lamella structures, ext ...19751236936
[new data on the structure and the budding of fv3 (frog virus 3) (author's transl)].the freeze-etching technique when applied to fv3 suspensions revealed the perfectly icosahedral structure of the viral nucleocapsids. this allowed a fine substructure suggesting the existence of numerous subunits of small dimensions to be detected at their surface. observations of the replicas of infected cells obtained by freeze-etching revealed modifications of the external face of the cytoplasmic membrane occurring at the level of the budding viral particles; in these zones parallel stripes a ...19751241755
proteins solubilized from frog virus 3 particles: effect on transcription.the treatment of kb cells with viral proteins solubilized from frog virus 3 particles (sve) induced a rapid shutoff of host rna synthesis. the rna polymerase activities of sve-treated cells were drastically depressed, corresonding, at least for rna polymerase b, to a decrease in the number of enzyme molecules. in vitro, sve had no direct effect on rna polymerases but was capable of binding with calf thymus dna to form an sve-dna complex modifying the template capacity. the effect of sve on a tra ...19761255875
metabolism of host and viral mrnas in frog virus 3-infected cells.treatment of purified frog virus 3 (fv3) with nonionic detergent and high salt released an endoribonucleolytic activity and confirmed earlier findings of a virion-associated endonuclease. this observation, coupled with evidence implicating host and viral message destabilization in herpesvirus and poxvirus biogenesis, raised the question of what role, if any, mrna degradation plays in fv3 replication. to answer this question, northern analyses of mock- and virus-infected cells were performed usin ...19921310177
cytoplasmic localization of the dna virus frog erythrocytic situ hybridization, using a biotinylated clone of frog erythrocytic virus (fev), was conducted to determine the location of viral sequences in bullfrog erythrocytes. fev-specific hybridization signals were found to correspond to mature cytoplasmic viral particles and assembly sites. these data are consistent with electron microscopic observations of viral assembly in the erythrocyte cytoplasm. although fev has morphological and biochemical properties similar to frog virus 3, our data suggest ...19921500276
ultrastructure of lymphocystis disease virus (ldv) as compared to frog virus 3 (fv3) and chilo iridescent virus (civ): effects of enzymatic digestions and detergent degradations.ultrastructure of fish lymphocystis disease virus (ldv), the largest of all known icosahedral viruses, has been studied under electron microscopy using enzymatic digestions and detergent degradations. ldv structure appeared roughly the same as those of frog virus 3 (fv3) and chilo iridescent virus (civ), two other well known viruses of the family iridoviridae, although the great flexibility of its capsid as observed on negatively stained and shadow cast particles, and its three electron dense la ...19921642551
a frog virus 3 gene codes for a protein containing the motif characteristic of the int family of integrases.the integrase (int) family of bacteriophage coded integrase-recombinase proteins are responsible for catalyzing strand exchange between dna molecules and play an important role in the dna replication of many bacteriophages. within the frog virus 3 (fv3) genome we have identified an open reading frame (orf) of which the deduced amino acid sequence contains a motif characteristic of the int family of integrases-recombinases. the orf consists of 825 bp which codes for a protein of 275 amino acids w ...19921733108
frog virus 3-mediated translational shut-off: frog virus 3 messages are translationally more efficient than host and heterologous viral messages under conditions of increased translational stress.frog virus 3 rapidly and selectively blocks host cell translation while synthesizing more than 60 virus-specific polypeptides. previous work indicated that virus infection led to activation of a kinase that phosphorylated and, as a consequence, inactivated eif-2. although phosphorylation of eif-2 could explain the rapid decline in host cell translation, it could not explain how viral protein synthesis persisted in the face of host shut-off. to explain this phenomenon, we speculated that viral me ...19902201134
translational efficiency: iridovirus early mrnas outcompete tobacco mosaic virus message in vitro.infection with the iridovirus, frog virus 3, results in the rapid inhibition of host cell protein synthesis and is correlated with activation of an eif-2 kinase. because phosphorylation of eif-2 inhibits ternary complex formation and thus reduces the overall level of translation, it has been suggested that frog virus 3 messages escaped translational shut-off by outcompeting host messages for the remaining translational capacity of the cell. in this report, we show that frog virus 3 messages were ...19902244916
the nucleotide sequence of a delayed early gene (31k) of frog virus 3. 19902374725
ultrastructural and biochemical evidence of the trimeric nature of frog virus 3 (fv3) six-coordinated capsomers.image analysis of freeze-etch replicas of cylindrical aberrant forms of fv3 provided evidence for three morphological subunits protruding from the six-coordinated capsomers. negatively stained capsomers displayed both triangular and hexagonal profiles which suggests that their innermost portion is pseudohexagonal. images from underfocused micrographs of capsomers are indicative of a central channel. the trimeric nature of the capsomer has been established by electrophoresis in the presence of tr ...19862418581
mutation in a dna-binding protein reveals an association between dna-methyltransferase activity and a 26,000-da polypeptide in frog virus 3-infected cells.the dna of frog virus 3 (fv3), an iridovirus, is highly methylated; more than 20% of the cytosine bases are methylated at the 5-carbon position by an fv3-induced dna methyltransferase (dna-mt). to determine the role of this enzyme in virus replication and regulation of gene expression, we have analyzed an fv3 mutant that lacks dna-mt activity and is resistant to 5-azacytidine (an inhibitor of dna-mt). comparative polypeptide analysis, using cytoplasmic extracts from the wild-type fv3 and mutant- ...19872445102
transcription of methylated viral dna by eukaryotic rna polymerase ii.the genome of the large icosahedral dna virus, frog virus 3 (fv3), is heavily methylated at the cytosine residues of dcdg dinucleotide pairs, with more than 22% of the total cytosine residues in the form of 5-methylcytosine (5mc). this methylation is carried out postreplicatively in the cytoplasm of infected cells by a virus-encoded dna methyltransferase. dna methyltransferase activity was shown to copurify with a 26 kd virus-induced, dna-binding protein that had an altered mobility in extracts ...19892476231
hemin and cyclic amp stimulate message-dependent translation in lysates from friend erythroleukemia cells.a message-dependent, cell-free translation system was prepared from both uninduced and n,n'-hexamethylene-bis-acetamide-induced friend erythroleukemia cells following modification of standard protocols. active extracts were prepared by lysing friend erythroleukemia cells in hypotonic buffer containing 50 microm hemin and 10 mm cyclic adenosine monophosphate (camp), and assaying translation in vitro in the absence of exogenous nucleoside triphosphates. both hemin and camp were required for full a ...19892541008
amphibian and piscine iridoviruses proposal for nomenclature and taxonomy based on molecular and biological properties.we have compared a number of properties of the well-characterized iridovirus, frog virus 3, with two other iridoviruses from amphibia, bullfrog edema virus and lucké triturus virus, and with a piscine iridovirus, goldfish virus (gfv), to provide information for developing taxonomic classification of these viruses and establishing their ecological niche. purified virions had similar size and shape (icosahedral) for each virus, and the genomic dnas of each virus were methylated by a virus-induced ...19892550386
frog virus 3-induced translational shut-off: activation of an eif-2 kinase in virus-infected cells.infection of susceptible fathead minnow or friend erythroleukemia cells with either infectious or heat-inactivated frog virus 3 led to the rapid inhibition of cellular protein synthesis. as seen in other cells, translational shut-off was accompanied by the dissociation of polysomes, but not the degradation of irreversible inactivation of cellular mrnas. in addition, lysates from cells infected with heat-inactivated fv3 showed a reduced capacity to synthesize protein and to form 43s pre-initiatio ...19892623941
synthesis of frog virus 3 proteins occurs on intermediate filament-bound polyribosomes.immunogold labeling and biochemical methods were used to localize the site of viral protein synthesis in frog virus 3 (fv3)-infected baby hamster kidney (bhk) cells. immunogold labeling studies of triton-extracted (cytoskeletons), fv3-infected bhk cells with antivimentin antibodies showed that the major components of the detergent-resistant residue are the intermediate filaments (if) and polyribosomes. double immunogold labeling studies with anti-fv3 and antivimentin antibodies revealed that fv3 ...19892752210
molecular cloning and physical and translational mapping of the frog virus 3 genome.a library of cloned fragments representing nearly the entire frog virus 3 (fv 3) genome (99.65%) has been constituted. individual plasmid recombinants, labeled by nick-translation, were hybridized to southern blots of genomic fv 3 dna fragments obtained with xbai, hindiii, smai, and sali. from these results physical maps were generated and the distribution of restriction sites in the genome was established by double digestion of the fragments. a preliminary translational map was likewise develop ...19882827372
structure and regulation of the immediate-early frog virus 3 gene that encodes test whether the promoters of two immediate-early genes from frog virus 3 were similar in nucleotide sequence, we have cloned and sequenced an immediate-early gene encoding an infected-cell mrna of 489 kilodaltons (icr489) and have shown that the protein product of this gene is approximately 46 kilodaltons. the 5' and 3' ends of the transcripts from this gene, as determined by mung bean nuclease analysis, were microheterogeneous. the promoter region was subcloned upstream from a promoterless ...19882831387
methylation of the promoter for an immediate-early frog virus 3 gene does not inhibit transcription.methylation of critical sites within the promoter region of eucaryotic genes has been shown to inhibit transcription by rna polymerase ii. however, although the large dna virus frog virus 3 (fv3) has a highly methylated genome, it uses host rna polymerase ii for at least the immediate-early stage of transcription. we have previously shown that an fv3-induced trans-acting protein allows transcription from adenovirus promoters inactivated by methylation. since fv3 immediate-early genes are transcr ...19882846879
a functional role for intermediate filaments in the formation of frog virus 3 assembly sites.during the course of frog virus 3 (fv3) infection in baby hamster kidney 21 (bhk) cells, vimentin-type intermediate filaments reorganize to surround the virus's cytoplasmic assembly sites. to determine whether the association between vimentin filaments and viral assembly sites has a functional role in the virus life-cycle, we treated cells with the antimicrotubule drugs taxol or colchicine, or injected them with monoclonal antivimentin antibodies prior to fv3 infection. each of these reagents ca ...19882892313
mapping of the gene coding for the major late structural polypeptide on the frog virus 3 genome.the gene encoding the major capsid polypeptide (mcp 48) of frog virus 3 (fv 3) has been mapped on the viral dna. late fv 3 messenger rna, hybrid-selected by the sali-f fragment or a subset of these sequences, bamhi-l and -w fragments, directed the synthesis in vitro of a 48 000 mol. wt. (48k) polypeptide. this product was recognized by monospecific antibodies raised against the major capsid polypeptide. the rna complementary to these dna sequences was about 1350 nucleotides in size. this transcr ...19863003238
leukotrienes as mediators in frog virus 3-induced hepatitis in rats.the role of leukotrienes was investigated in frog virus 3-induced hepatitis in rats. frog virus 3 elicited an enhanced generation of cysteinyl leukotrienes in vivo as monitored by measurement of n-acetyl-leukotriene e4 as the major endogenous metabolite of cysteinyl leukotrienes secreted into rat bile. n-acetyl-leukotriene e4 concentrations were elevated for more than 4 hr after frog virus 3 injection. in vitro experiments using cultured rat liver kupffer cells of high purity indicated that thes ...19873111968
the iridovirus frog virus 3: a model for trans-acting proteins.the amphibian iridovirus, frog virus 3 (fv3), produces at least two trans-activating proteins that stimulate the expression of viral genes. one of these proteins induces transcription from the promoter of an immediate-early fv3 gene, whereas the other induces transcription from exogenously methylated dna. these proteins may serve as a model for both viral and cellular trans-acting factors.19863153144
association of african swine fever virus with the cytoskeleton.the association of african swine fever virus (asfv) with the cytoskeleton was investigated. immunofluorescent studies of asfv infected cells with anti-asfv serum showed a temporal and spatial development of viral inclusions which moved from a peripheral to a perinuclear location and fused to give a single large perinuclear factory. the migration and fusion of viral inclusions was inhibited by colchicine suggesting a function for microtubules in assembly site organization not previously described ...19883201825
kupffer cell function in host defense.high-resolution in vivo microscopic methods have been used to explore the responses to endotoxin of kupffer cells in the livers of anesthetized mice, rats, hamsters, and guinea pigs under a variety of experimental conditions. these include studies of normal animals as well as of animals sensitized or tolerant to endotoxin, c3h/hej mice with a low response to endotoxin, mice rendered septic by cecal ligation and puncture, mice with kupffer cells selectively destroyed by frog virus 3, and rats wit ...19873317754
organization of rna transcripts from a 7.8-kb region of the frog virus 3 genome.the detailed organization of the rnas transcribed from a region of the fv 3 genome (sa/i-f fragment and adjacent sequences) has been determined. the information was derived from the cell-free translation of hybrid-selected rna to locate the genes encoding specific polypeptides, rna filter hybridization to size the transcripts, and s1 nuclease mapping to locate the 5'- and 3'-ends of the rnas on the genome. three genes are contiguous and are transcribed from the same strand: two immediate early g ...19883388766
trans-activation of a methylated adenovirus promoter by a frog virus 3 protein.the high degree of methylation of the frog virus 3 (fv3) genome suggests that fv3-infected cells are capable of transcribing highly methylated dna. we tested this hypothesis by assaying the transcriptional activity of adenovirus promoters known to be inhibited by methylation. plasmid constructs containing the e1a and e2ae promoters of adenovirus type 12 linked to the gene for chloramphenicol acetyltransferase [(cat) ec], when methylated and introduced into eukaryotic cells, promoted cat ...19863463992
dna sequences required for trans-activation of an immediate-early frog virus 3 gene.a plasmid containing 78 bp of the promoter region of the immediate-early frog virus 3 (fv3) gene icr 169 placed 5' to the coding sequences for chloramphenicol acetyltransferase (cat) can only be induced to synthesize cat after transfection in the presence of fv3. to determine what dna sequences in the promoter were required for virus-induced transcription, i used site-directed mutagenesis to construct deletions and point mutations throughout the promoter region. the mutant promoters were then an ...19873478893
interaction of frog virus 3 with the cytomatrix. iv. phosphorylation of vimentin precedes the reorganization of intermediate filaments around the virus assembly sites.frog virus 3 (fv3) assembles in morphologically distinct assembly sites in the cytoplasm of infected cells. as the assembly sites form, the intermediate filaments (if) aggregate, delimit the assembly sites, and remain so throughout infection. to determine the molecular basis of reorganization of if, we analysed the vimentin of uninfected and fv3-infected cells by two-dimensional gel electrophoresis. the results showed that (i) the vimentin was more acidic in fv3-infected cells than in uninfected ...19863517225
restriction of frog virus 3 polypeptide synthesis to immediate early and delayed early species by supraoptimal temperatures.multiplication of frog virus 3 (fv 3) occurs in mammalian cells provided they are incubated at temperatures lower than 33 degrees. the expression of the viral genome at supraoptimal temperatures was followed by analyzing the polypeptides produced in cho-infected cells and comparing with those obtained under restrictive conditions provoked by amino acid analogs or metabolic inhibitors. late polypeptides were not detected at 33 degrees and the number of delayed early species decreased gradually wi ...19863523970
thermosensitivity of frog virus 3 genome expression: defect in early transcription.the influence of temperature on the transcription of the frog virus 3 genome was studied in cho cells infected both at 29 and at 37 degrees, the nonpermissive temperature for virus multiplication. it was definitely established that late genes were not transcribed at 37 degrees. although immediate early genes were expressed at 37 degrees, their transcription was altered but there was no sequestration of mrnas in the nucleus which could impair their translation; these viral mrnas were also efficie ...19863523971
infection with frog virus 3 allows transcription of dna methylated at cytosine but not adenine residues.the genome of the iridovirus, frog virus 3, is highly methylated at cytosine residues by a virus-encoded dna methyltransferase. we have shown previously that an fv3-induced trans-acting protein alters either host rna polymerase ii or methylated template to allow transcription from promoters inactivated by methylation. we now present evidence that the ability of fv3-infected cells to transcribe methylated dna is specific for dna methylated at cytosine residues. eukaryotic promoters were inactivat ...19873629976
heat-inactivated frog virus 3 selectively inhibits equine herpesvirus type 1 translation in a temporal class-dependent manner.superinfection of equine herpesvirus type 1 (ehv-1)-infected rabbit kidney cells with heat-inactivated frog virus 3 (delta fv3) differentially blocked ehv-1 protein synthesis. the extent of inhibition varied with the specific ehv-1 message, but in general late protein synthesis was inhibited more than early and immediate early translation. since fv3 has been shown to block heterologous rna and protein synthesis, it was necessary to determine whether the observed reduction in herpesvirus protein ...19863727402
phagocytosis, an unrecognized property of murine endothelial liver cells.impairment of the phagocytic capacities of kupffer cells, as is found in frog virus 3 hepatitis of mice, allows the endothelial liver cells to take up intravenously inoculated latex particles of 1.0 micron diameter. in vitro experiments with cultivated endothelial cells isolated by collagenase perfusion of the liver and purified by centrifugal elutriation demonstrate that uptake occurs via a typical mechanism of phagocytosis involving pseudopodia. ingestion of latex is inhibited by incubation of ...19863758936
trans activation of an immediate-early frog virus 3 promoter by a virion protein.we investigated the protein and dna sequence requirements for the expression of an immediate-early frog virus 3 (fv3) gene, infected-cell rna (icr) 169. we used a plasmid containing the 78 nucleotides 5' to the transcription start site of icr-169 placed upstream from the coding sequence for the bacterial enzyme chloramphenicol acetyltransferase (cat). this construction, when introduced by capo4-mediated transfection into various eucaryotic cell lines, promoted cat synthesis only if the transfect ...19853863966
interaction of frog virus 3 with the cytoskeleton. 19853893906
macromolecular synthesis in cells infected by frog virus 3. 19853893912
ultrastructural and biochemical study of frog virus 3 uptake by bhk-21 cells.ultrastructural studies of the uptake of enveloped and naked frog virus 3 (fv 3) particles by bhk-21 cells have shown that enveloped viruses are internalized by adsorptive endocytosis via coated pits. the enveloped particles then appear to move through endosomes and finally lysosomes. naked viruses may also follow the same pathway but only rarely. their more frequent mode of entry is by fusion between the virus shell and the cellular membranes, thus allowing the virus to shed its nucleoprotein c ...19853918142
temperature-sensitive mutants of frog virus 3: biochemical and genetic characterization.nineteen frog virus 3 temperature-sensitive mutants were isolated after mutagenesis with nitrosoguanidine and assayed for viral dna, rna, and protein synthesis, as well as assembly site formation at permissive (25 degrees c) and nonpermissive (30 degrees c) temperatures. in addition, mutants were characterized for complementation by both quantitative and qualitative assays. based on the genetic and biochemical data, the 19 mutants, along with 9 mutants isolated earlier, were ordered into four ph ...19863951023
interaction of frog virus 3 with the cytomatrix. iii. role of microfilaments in virus release.the role of microfilaments in the release of frog virus 3 (fv3) from the plasma membrane was studied. scanning electron microscopic study of fv3-infected baby hamster kidney (bhk) cells showed that late in infection (15 hr), numerous microvillus-like projections containing virions and microfilaments occur on the cell surface. two microfilament-disrupting drugs, cytochalasin b and cytochalasin d, inhibited both the formation of microvillus-like projections and virus release. in the drug-treated c ...19854060576
proteins of a polyhedral cytoplasmic deoxyvirus. 3. structure of frog virus 3 and location ov virus-associated adenosine triphosphate phosphohydrolase.the adenosine triphosphatase associated with frog virus 3 shows high specificity for atp or deoxyadenosine triphosphate and appears to be distinct from the corresponding activity in host cells, poxvirus, or reovirus. the enzyme activity is probably integrated into virus particles since it is firmly associated with subviral particles produced when approximately 50 to 60% of the outer viral protein is removed by detergent treatment. the occurrence of adenosine triphosphatase activity within three ...19714108931
[ultrastructure of frog virus 3 (fv3)]. 19734124866
viruses and renal carcinoma of rana pipiens. 3. the relationship between input multiplicity of infection and inclusion body formation in frog virus 3-infected cells. 19674166975
[correlation between the location of antigens detected by immunofluorescence and the ultrastructural stages of the morphogenesis of fv 3 (frog virus 3)]. 19744211371
[demonstration of surface antigens in bhk 21 cells infected with fv 3 (frog virus 3), using the mixed agglutination technic]. 19744212605
macromolecular synthesis in cells infected by frog virus 3. i. virus-specific protein synthesis and its regulation. 19744276315
proteins of polyhedal cytoplasmic deoxyvirus. ii. nucleotide phosphohydrolase activity associated with frog virus 3.a nucleotide phosphohydrolase is firmly associated with a purified polyhedral cytoplasmic deoxyvirus, frog virus 3. this adenosine triphosphatase is distinguishable from known mammalian cell adenosine triphosphatases and from adenosine triphosphatase of an unrelated cytoplasmic replicating virus grown in the same host cell. the enzyme activity has a high specificity for adenosine triphosphate; the product of the reaction is adenosine diphosphate. the presence of similar activities in reovirus an ...19714327890
degradation of single- and double-stranded rna by frog virus 3.purified preparations of frog virus 3 possess ribonuclease activities directed against single-and double-stranded rna. double-stranded rnas isolated from purified reovirus type 3 and from hela cells infected with poliovirus and single-stranded poliovirus rna from purified virus are readily degraded by incubation with frog virus 3. the mode of action of the nucleases is endonucleolytic. under the assay conditions used for the viral enzyme, crude extracts of uninfected hela, l, and baby hamster ki ...19724335069
virus-associated nucleases: location and properties of deoxyribonucleases and ribonucleases in purified frog virus least three nuclease activities are associated with purified frog virus 3. these activities are endodeoxyribonuclease (ph 7.5, double-stranded [ds] and single-stranded [ss] deoxyribonucleic acid [dna]); endodeoxyribonuclease (ph 5.0, ds and ss dna); endoribonuclease (ds and ss ribonucleic acid [rna], ph 7.5). these activities are not adsorbed to the surface of the virion but are within the viral capsid and require detergent disruption of virions to unmask enzyme activity. only one activity, d ...19724342238
phosphorylation of animal virus proteins by a virion protein kinase.compared with several other enveloped viruses, purified virions of frog virus 3 contained a relatively high activity of a protein kinase which catalyzed the phosphorylation of endogenous polypeptides or added substrate proteins. virions also contained a phosphoprotein phosphatase activity which released phosphate covalently linked to proteins. it was possible to select reaction conditions where turnover of protein phosphoesters was minimal, as the phosphatase required mn(2+) ions for activity wh ...19734355852
the effect of frog virus 3 on the biological activity of various rna viruses. 19734357374
electron microscopic observations on early events of frog virus 3 replication. 19744362435
inhibition of simian virus 40 dna synthesis by frog virus 3. 19744365490
inhibition of foot-and-mouth disease virus replicase by frog virus 3 particles. 19744367303
lipid composition of frog virus 3. 19744472187
electron microscopic studies on frog virus 3 infection in hela cells at permissive and non-permissive temperatures. 19744474866
budding of frog virus 3 studied by immunological and cytochemical methods in electron microscopy. 19744475038
viruses and renal carcinoma of rana pipiens. xiv. temperature-sensitive mutants of frog virus 3 with defective encapsidation. 19734542031
early ultrastructural changes induced in bhk cell nuclei by frog virus 3. a possible mechanism for the impairment of cellular dna synthesis. 19734543391
acute hepatitis produced by frog virus 3 in mice. brief report. 19724553583
impairment of host cell ribonucleic acid polymerase ii after infection with frog virus 3.evidence is presented that, in frog virus 3-infected bhk cells, inhibition of ribonucleic acid (rna) synthesis is paralleled by a decreased activity of host cell rna polymerase ii, while the template ability of host cell nuclei and chromatin is unaffected.19724553680
[early ultrastructural changes in the nuclei of mouse hepatocytes during acute degenerative hepatitis induced by fv3 (frog virus 3)]. 19734588127
[histological and virological study of acute degenerative hepatitis produced by the fv3 (frog virus 3) in mice]. 19724625136
[inhibition of cellular protein synthesis in kb cells infected by frog virus 3 (fv3)]. 19724632291
[immunization of mice against acute degenerative hepatitis induced by fv3 (frog virus). methods and results of vaccination]. 19734729290
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