| nucleotide sequence, insertional mutagenesis, and transcriptional mapping of a conserved region of the baculovirus autographa californica nuclear polyhedrosis virus (map unit 64.8-66.9). | the nucleotide sequence of a 2773-bp region of the autographa californica nuclear polyhedrosis virus hr3 variant (acmnpv) (map unit 64.4-68.2) has been determined. this region lies between the previously analyzed p6.9 and p80 genes. three open reading frames were contained within this region, potentially coding for proteins of 45, 40, and 12 kda. the 5' ends of transcripts capable of coding for the 45- and 12-kda proteins map to consensus baculovirus late transcription start sites (ataag), while ... | 1996 | 8989865 |
| role of early and late replication events in induction of apoptosis by baculoviruses. | autographa californica nuclear polyhedrosis virus (acmnpv) mutants that lack the apoptotic suppressor gene p35 cause apoptosis in spodoptera frugiperda sf21 cells. to identify a viral signal(s) that induces programmed cell death, we first defined the timing of apoptotic events during infection. activation of a p35-inhibitable caspase, intracellular fragmentation of host and acmnpv dna, and cell membrane blebbing coincided with the initiation of viral dna synthesis between 9 and 12 h after infect ... | 1997 | 8995679 |
| the genes encoding the p39 and cg30 proteins of bombyx mori nuclear polyhedrosis virus. | we have cloned and analysed the transcriptional properties of two closely linked genes, p39 and cg30, of bombyx mori nuclear polyhedrosis virus (bmnpv). these genes encode a structural polypeptide and a putative transcriptional regulator of the virus, respectively. the cg30 gene is transcribed prior to and after dna replication from a site located within the orf of the adjacent p39 gene. its transcription product, a 1.3 kb mrna, is polyadenylated at a site containing consensus eukaryotic polyade ... | 1996 | 9000108 |
| association of a baculovirus-encoded protein with the capsid basal region. | an open reading frame homologous to acmnpv orf9 (orf1629) was characterized in the orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus (opmnpv). sequence analysis indicated that the opmnpv homolog (called orf2) encoded a protein predicted to contain 545 amino acids with a molecular weight of 61 kda. the first 80 amino acids did not have a counterpart in the acmnpv homolog. the remainder of the orf was poorly conserved with 29% amino acid identity overall with the acmnpv orf. howeve ... | 1997 | 9007067 |
| detection and identification of multiple baculoviruses using the polymerase chain reaction (pcr) and restriction endonuclease analysis. | a technique using the polymerase chain reaction (pcr) and restriction analysis was developed for the simultaneous detection of eight baculoviruses. the baculoviruses detected by this technique were autographa californica multiple-embedded nuclear polyhedrosis virus (mnpv). anticarsia gemmatalis mnpv, bombyx mori mnpv, orgyia pseudotsugata mnpv. spodoptera frugiperda mnpv, s. exigua mnpv, anagrapha falcifera mnpv, heliothis zea single-embedded nuclear polyhedrosis virus (snpv). a highly conserved ... | 1997 | 9015292 |
| autographa californica nuclear polyhedrosis virus p143 gene product is a dna-binding protein. | we have identified the protein product of the autographa californica nuclear polyhedrosis virus (acmnpv) p143 gene by constructing a recombinant baculovirus overexpressing the gene product p143. the overexpressed protein exhibited a relative mobility of approximately 140 kda and was stable for at least 12 hr after synthesis. immunoblotting using a monoclonal antibody developed against the overexpressed protein identified a similar polypeptide in acmnpv-infected cells which was detectable by 4 hr ... | 1997 | 9024814 |
| establishment of a cell line from spodoptera litura (lepidoptera: noctuidae) and replication of s. litura nuclear polyhedrosis virus in vitro. | a new cell line, designated ibl-slo1a, was established from pupal ovaries of the tobacco cutworm spodoptera litura. cells were grown in the tnm-fh insect cell culture medium supplemented with 10% fetal bovine serum. the subculture of cells was initiated with 1-3 x 10(5) cells/ml, a split ratio about 1:10. the growth curve of the cells fit the model of exponential growth (y = e-0.6750 + 0.0317x r2 = 0. 98), the population doubling time during logarithmic growth at 28 degrees c was 21.9 hr. the nu ... | 1997 | 9028921 |
| replication of anticarsia gemmatalis nuclear polyhedrosis virus in four lepidopteran cell lines. | anticarsia gemmatalis nuclear polyhedrosis virus (agnpv; family baculoviridae) is pathogenic for larvae of the velvetbean caterpillar, anticarsia gemmatalis hübner-an important pest of soybean. agnpv is a viable alternative to chemical control of a. gemmatalis in brazil, where its use as a pesticide has brought significant economic and environmental benefits. although a significant amount of information is available on the ecological and biological control aspects of agnpv, very little is known ... | 1997 | 9028926 |
| characterization of a domain of the genome of bmnpv containing a functional gene for a small capsid protein and harboring deletions eliminating three open reading frames that are present in acnpv. | the nucleotide sequence of a 1.5-kb fragment of the genome of bombyx mori nuclear polyhedrosis virus (bmnpv) has been determined. an open reading frame (orf) has been identified, which encodes a protein of a predicted molecular mass of 15 kda (p15). analysis of the p15 sequence revealed that it shares significant similarities with a number of previously characterized viral capsid proteins. two mrnas, 0.7- and 1.3-kb, are transcribed from the p15 gene. the 0.7-kb transcript appears before bmnpv d ... | 1997 | 9034315 |
| expression of the mouse interleukin-2 receptor gamma chain in insect cells using a baculovirus expression vector--comparison with the human common gamma chain. | the gene encoding the gamma-chain of the mouse interleukin-2 receptor was expressed in lepidopteran insect cells using the baculovirus expression vector system. the corresponding gene was inserted under the polyhedrin promoter of the autographa californica nuclear polyhedrosis virus and expressed in the spodoptera frugiperda insect cell line sf9 during viral infection. the recombinant receptor protein was identified by immunoblotting in cell lysates prepared from insect cells infected with the p ... | 1997 | 9042425 |
| maturation of the dengue-2 virus ns1 protein in insect cells: effects of downstream ns2a sequences on baculovirus-expressed gene constructs. | a series of recombinant baculoviruses was constructed in order to study the influence of downstream ns2a sequences on the processing of the dengue virus ns1 glycoprotein in insect cells. ns1 alone was expressed at a high level in its native dimeric form and processed efficiently through the spodoptera frugiperda (sf) cell secretory pathway. recombinant ns1 was found associated with the plasma membrane and was also secreted into the extracellular medium. although both intra- and extracellular ns1 ... | 1995 | 9049346 |
| effect of methyltransferase inhibitors on the regulation of baculovirus protein synthesis. | in the presence of the methyltransferase inhibitor 3-deazaadenosine (3da-ado) the production of infectious autographa californica nuclear polyhedrosis virus (acmnpv) in tissue culture was only slightly affected, while the synthesis of very late proteins (polyhedrin and p10) was abolished. the synthesis of the influenza virus proteins ns1 and ha, expressed under the polyhedrin promoter, was also abolished by 3da-ado. furthermore, 3da-ado interfered with the shut-off of early and late acmnpv prote ... | 1995 | 9049353 |
| detection of antibodies against porcine parvovirus nonstructural protein ns1 may distinguish between vaccinated and infected pigs. | the humoral antibody response against the nonstructural protein ns1 and the structural protein vp2 of porcine parvovirus (ppv) was evaluated by immuno-peroxidase test (ipt) and enzyme linked immuno sorbent assay (elisa) using recombinant ppv antigens. the coding sequence for ns1 and vp2 was inserted into the baculovirus. autographa californica nuclear polyhedrosis virus (acnpv) genome resulting in two recombinant baculoviruses acnpv-ns1 and acnpv-vp2, respectively. sf9 cells (spodoptora frugidip ... | 1997 | 9050166 |
| enhanced bioactivity of recombinant baculoviruses expressing insect-specific spider toxins in lepidopteran crop pests | two genetically enhanced isolates of the autographa californica nuclear polyhedrosis virus (acmnpv) expressing insect-specific neurotoxin genes from the spiders diguetia canities and tegenaria agrestis were evaluated for their commercial potential. since prevention of feeding damage is of primary importance in assessing agronomic efficacy, a method for estimating the median time to cessation of feeding (ft50) was developed. neonate droplet feeding assays with preoccluded virus samples were condu ... | 1997 | 9056461 |
| microbial contamination in spodoptera littoralis nuclear polyhedrosis virus produced in insects in egypt | spodoptera littoralis nuclear polyhedrosis virus produced in egypt, for use in field trials for the control of s. littoralis on cotton, was subject to microbiological examination to quantify microbial contamination. bacteria were found to be present at 10(6)-10(9) colony-forming units/ml in virus suspensions containing 2.1 x 10(9) polyhedral inclusion bodies/ml. batches were found to contain between 2 and 11 different species of contaminant microbes. no primary human pathogens of medical importa ... | 1997 | 9056465 |
| polyomavirus major capsid protein vp1 is capable of packaging cellular dna when expressed in the baculovirus system. | using the p2bac dual multiple cloning site transfer vector, the polyomavirus major capsid protein gene vp1 was cloned for expression in the baculovirus-insect cell expression system. the 5-day-infected cellular lysate from this recombinant preparation was purified by cesium chloride density gradient centrifugation. capsid-like particles were observed in the resulting preparation. the purified particle preparation was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was s ... | 1997 | 9060642 |
| characterization of the interaction between the baculovirus replication factors lef-1 and lef-2. | the autographa californica multinucleocapsid nuclear polyhedrosis virus has six genes required and three genes stimulatory for transient dna replication. we demonstrate that the products of two of these genes, lef-1 and lef-2, interact in both two-hybrid assays using saccharomyces cerevisiae and glutathione s-transferase fusion affinity assays. using yeast-two-hybrid assays, we mapped the interaction domain of lef-2 to amino acids between positions 20 and 60. extensive deletion analyses of lef-1 ... | 1997 | 9060674 |
| expression of rat steroid 5 alpha-reductase (isozyme-1) in spodoptera frugiperda, sf21, insect cells: expression of rat steroid 5 alpha-reductase. | the enzyme steroid 5 alpha-reductase (5 alpha r) catalyzes the reduction of testosterone (t) to 5 alpha-dihydrotestosterone (dht). in this study, the baculovirus expression system was used to overexpress rat 5 alpha r type i isozyme (r5 alpha r 1). the full length of r5 alpha r1 cdna was inserted into the autographa californica nuclear polyhedrosis virus (ac-mnpv) genome and expressed in spodoptera frugiperda, sf 21, insect cells. the expressed recombinant r5 alpha-r1 showed maximal enzymatic ac ... | 1997 | 9090798 |
| [comparative characteristics of nuclear polyhedrosis virus isolates from gypsy moth lymantria dispar l]. | eight strains of gypsy moth nuclear polyhedrosis virus (npv) were isolated from dead larvae in kirghizia and tyumen and novosibirsk districts. the strains were characterized in terms of polyhedron morphology, biological activity, virus production, and restriction analysis of dna. the isolated strains did not differ in size or shape of polyhedrons. npv strain nshn-2 was characterized by the highest biological activity (ld50 = 1.2 +/- 0.4) x 10(4) and maximum production: 7.3 x 10(8) pib/larva in c ... | 1997 | 9103045 |
| genetic variability of four natural isolates of the stilpnotia salicis multiple-enveloped nuclear polyhedrosis virus. | viral genome dna from four different multiple-enveloped nuclear polyhedrosis virus isolates, obtained from naturally infected larvae of satin moth (stilpnotia salicis), a pest of poplar tree (populus) was analysed. larvae were collected over a period of 11 years, from 1978 to 1989. the genomic dna restriction patterns pointed to heterogeneity of these wild-type viruses. the differences observed in isolates of several years revealed limited restriction fragment length polymorphism and showed that ... | 1996 | 9104499 |
| expression of foreign proteins on the surface of autographa californica nuclear polyhedrosis virus. | based on the method of direct cloning into the baculovirus genome by linearizing and re-ligation in presence of the target insert, we designed viral constructs that express foreign genes on the surface of baculovirus particles. we chose the glycosylated envelope protein gp41 of human immunodeficiency virus type 1 (hiv-1) as a model for displaying recombinant proteins on budded virus. the ectodomain of the envelope protein gp41 of hiv-1 was being fused to the entire baculovirus major coat protein ... | 1997 | 9105625 |
| n-terminal sequences from autographa californica nuclear polyhedrosis virus envelope proteins odv-e66 and odv-e25 are sufficient to direct reporter proteins to the nuclear envelope, intranuclear microvesicles and the envelope of occlusion derived virus. | baculovirus occlusion-derived virus (odv) derives its envelope from an intranuclear membrane source. n-terminal amino acid sequences of the autographa californica nuclear polyhedrosis virus (acmnpv) envelope proteins, odv-e66 and odv-e25 (23 and 24 amino acids, respectively) are highly hydrophobic. recombinant viruses that express the two n-terminal amino acid sequences fused to green fluorescent protein (23gfp or 24gfp) provided visual markers to follow protein transport and localization within ... | 1997 | 9108103 |
| organization and molecular characterization of genes in the polyhedrin region of the anagrapha falcifera multinucleocapsid npv. | a multinucleocapsid nuclear polyhedrosis virus (mnpv) isolated from the celery looper, anagrapha falcifera, has been proposed as a new virus based on differences in virulence and dna fragment profiles between this isolate and the autographa californica mnpv, the mnpv type species. in the present study, we examined the relatedness of the afmnpv and acmnpv genomes by (1) southern hybridization, (2) comparison of their genetic organization in the polyhedrin gene region (acmnpv ecori-i fragment), an ... | 1997 | 9125047 |
| the sequence of the orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus genome. | the nucleotide sequence of the orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus (opmnpv) genome was completed and analyzed. it is composed of 131,990 bases with a g + c content of 55% and contains 152 putative genes of 150 nucleotides or greater. major differences in gene content and arrangement between opmnpv and the autographa californica mnpv were found. these include the presence in opmnpv of three complete iap gene homologs, two conotoxin gene homologs, two protein tyrosine ... | 1997 | 9126251 |
| deletion analysis of four of eighteen late gene expression factor gene homologues of the baculovirus, bmnpv. | nucleotide sequence analysis of the genome of the baculovirus bombyx mori nuclear polyhedrosis virus (bmnpv) identified 18 homologues of the autographa californica npv (acnpv) lefs (late expression factor genes). these bmnpv lefs showed high (73-98%) amino acid sequence identities to acnpv lefs and were localized to similar positions in the genome. one lef, p35, was previously characterized in acnpv and bmnpv deletion experiments. functional deletion of each of the bmnpv lef homologues was attem ... | 1997 | 9126260 |
| baculovirus-mediated trans-epithelial transport of proteins in infected caterpillars. | baculovirus-mediated abnormal protein trafficking was studied in infected caterpillars by using heterologous proteins. the gene for human complement c1r was expressed in larvae of mamestra brassicae by a recombinant autographa californica nuclear polyhedrosis virus (acmnpv) vector. by following the time-course of recombinant c1r distribution among various tissues, cell types and cell organelles, we concluded that the dominant site of recombinant protein synthesis was the fat body, although some ... | 1997 | 9129671 |
| baculovirus inhibitor of apoptosis functions at or upstream of the apoptotic suppressor p35 to prevent programmed cell death. | members of the inhibitor of apoptosis (iap) gene family prevent programmed cell death induced by multiple signals in diverse organisms, suggesting that they act at a conserved step in the apoptotic pathway. to investigate the molecular mechanism of iap function, we expressed epitope-tagged op-iap, the prototype viral iap from orgyia pseudotsugata nuclear polyhedrosis virus, by using novel baculovirus recombinants and stably transfected insect cell lines. epitope-tagged op-iap blocked both virus- ... | 1997 | 9151843 |
| late promoter selection in the baculovirus gp64 envelope fusion protein gene. | the upstream promoter region of the autographa californica multicapsid nuclear polyhedrosis virus (acmnpv) gp64 gene contains five copies of taag, the conserved sequence found at the transcriptional initiation sites of almost all baculovirus late genes. in acmnpv-infected sf9 cells, late transcription initiation is detected from only two upstream taag sites and not from three downstream taag sites. to examine several models for preferential taag site utilization, we constructed a series of recom ... | 1997 | 9168879 |
| loading of iron into recombinant rat liver ferritin heteropolymers by ceruloplasmin. | we have reported previously that the heavy chain of ferritin is required for iron incorporation by ceruloplasmin (j.-h. guo, m. abedi, and s. d. aust (1996) arch. biochem. biophys. 335(1)). the purpose of this study was to determine how many heavy chains were required for ceruloplasmin to interact with ferritin such that iron loading occurred. the cdna sequences encoding the heavy and light chains of rat liver ferritin were cloned into the baculovirus transfer vector pa-cuw51 under the control o ... | 1997 | 9169016 |
| [transgenerational transfer of gypsy moth (ocneria dispar l.) nuclear polyhedrosis virus]. | gypsy moth nuclear polyhedrosis virus infects egg laying under natural conditions. the virus was identified by restriction endonucleases pst1, bamh1, and sal1. | 1997 | 9182408 |
| expression of lacz reporter gene under the control of the polyhedrin promoter of spodoptera litura nuclear polyhedrosis virus. | promoter function of the putative polyhedrin-encoding gene (polh) of spodoptera litura nuclear polyhedrosis virus (s1mnpv) was determined by transferring it to the autographa californica nuclear polyhedrosis virus (acmnpv) through the acnpv polh based vector, pvl1393. three transfer vectors pcbt2, pcbt3 and pcbt4 were constructed by substituting the promoter and the neighbouring sequences of acnpv in pvl1393 by that of s1npv. the escherichia coli lacz gene was placed downstream from the s1npv po ... | 1997 | 9185860 |
| sequencing of the putative dna helicase-encoding gene of the bombyx mori nuclear polyhedrosis virus and fine-mapping of a region involved in host range expansion. | the complete sequence of a 3666-nucleotide (nt) open reading frame (orf) and its flanking regions (58.1-62.1 map units (m.u.) from bombyx mori nuclear polyhedrosis virus (bmnpv)) was determined. this orf, bmnpv dnahel, encoded a predicted protein of 143623 da which possessed seven consensus motifs found in proteins which unwind duplex dnas, indicating that it is a dna helicase. a 572-bp saci-hindiii fragment, bmsch, that was previously shown to expand the host range of autographa californica npv ... | 1997 | 9185864 |
| heterologous promoter recognition leading to high-level expression of cloned foreign genes in bombyx mori cell lines and larvae. | the baculovirus expression system using the autographa californica nuclear polyhedrosis virus (acnpv) has been extensively utilized for high-level expression of cloned foreign genes, driven by the strong viral promoters of polyhedrin (polh) and p10 encoding genes. a parallel system using bombyx mori nuclear polyhedrosis virus (bmnpv) is much less exploited because the choice and variety of bmnpv-based transfer vectors are limited. using a transient expression assay, we have demonstrated here tha ... | 1997 | 9185865 |
| identification and characterization of a baculovirus structural protein, vp1054, required for nucleocapsid formation. | the defect in a temperature-sensitive mutant of autographa californica nuclear polyhedrosis virus, tsn1054, was mapped and characterized. at the nonpermissive temperature of 33 degrees c, this mutant fails to form plaques upon infection of sf-21 cultured insect cells; infection is limited to a single cell, even though the infection proceeds through the very late phase. marker rescue mapping and dna sequencing identified the gene, orf 54, which was altered by a single nucleotide substitution in t ... | 1997 | 9188569 |
| a mechanism for negative gene regulation in autographa californica multinucleocapsid nuclear polyhedrosis virus. | the autographa californica multinucleocapsid nuclear polyhedrosis virus (acmnpv) ie-1 gene product (ie-1) is thought to play a central role in stimulating early viral transcription. ie-1 has been demonstrated to activate several early viral gene promoters and to negatively regulate the promoters of two other acmnpv regulatory genes, ie-0 and ie-2. our results indicate that ie-1 negatively regulates the expression of certain genes by binding directly, or as part of a complex, to promoter regions ... | 1997 | 9188574 |
| dna replication promotes high-frequency homologous recombination during autographa californica multiple nuclear polyhedrosis virus infection. | the relative ease with which foreign genes can be incorporated into the genome of the baculovirus autographa californica nuclear polyhedrosis virus (acmnpv) indicates that a highly efficient recombinational process exists within infected cells. however, it is unclear whether this is due to marker transfer mediated by host cell enzymes or recombination events promoted by acmnpv itself. to address the latter possibility, a pair of inverted repeat is50 elements derived from the bacterial transposon ... | 1997 | 9191843 |
| baculovirus transactivator ie1 is functional in mammalian cells. | ie1 of autographa californica multicapsid nuclear polyhedrosis virus acts as a transactivator of several viral promoters in insect cells. transient expression assays indicate that ie1 is involved in the activation of the early promoter he65 in both insect tn-368 and mammalian bhk-21 cell lines. ie1 activation of the he65 promoter was compared with ie1 activation of the early 39k promoter. in contrast to the he65 promoter, the 39k promoter was not inducible by ie1 in bhk-21 cells. | 1997 | 9191949 |
| characterization of p91, a protein associated with virions of an orgyia pseudotsugata baculovirus. | polyclonal antiserum produced against preoccluded virions from the orgyia pseudotsugata multinucleocapsid nuclear polyhedrosis virus (opmnpv) was used to screen an opmnpv lambda gt11 expression library. the insert from one of the immunoreactive phage isolates hybridized to opmnpv orf86 (p91), a 2460-bp (819 amino acids) open reading frame that encodes a predicted protein of 91 kda. antibodies generated against a maltose binding protein-p91 fusion detected a band of approximately 91 kda on wester ... | 1997 | 9201231 |
| differential requirements of two insect cell lines for growth in serum-free medium. | the development of a serum-free medium that supports the growth of cells from a spodoptera frugiperda and a lymantria dispar cell line is reported. a yeast hydrolysate provided the b-vitamin complex, and a combination of a meat hydrolysate and tryptose provided most of the free amino acids required for cell growth. supplemental cystine and methionine were required to achieve maximum cell growth. the serum or serum replacements used in earlier formulations were replaced with commercial lipid prep ... | 1997 | 9201517 |
| [expression of cdna of human chorionic gonadotropin beta-subunit (beta-hcg) cdna in insect cells and effect of expressed product on mouse lymphocytes in vitro]. | expression vector pvl 1393-hcg beta containing beta-hcg cdna has been constructed using an unfused protein nuclear polyhedrosis virus (acnpv) expression vector. the insect cells (sf 9) were cotransfected by the expression vector and nuclear polyhedrosis virus genomic dna, and recombinant virus acnpv-hcg beta was screened out, beta-hcg cdna was expressed in insect cells infected by recombinant virus and recombinant beta-hcg (r beta-hcg) was secreted into medium. the purity of r beta-hcg, purified ... | 1996 | 9208644 |
| a role for baculovirus gp41 in budded virus production. | insect cells infected with tsb1074, a temperature-sensitive mutant of autographa californica nuclear polyhedrosis virus, exhibit a "single-cell-infection" phenotype whereby the infection progresses through the very late phase culminating in occlusion body formation, but neighboring cells do not become infected. marker rescue mapping and dna sequencing correlated a single nucleotide substitution within the baculovirus gp41 gene with the temperature-sensitive phenotype of tsb1074. the product of t ... | 1997 | 9217053 |
| complete sequence and transposon mutagenesis of the bamhi j fragment of cydia pomonella granulosis virus. | the bamhi j fragment of cydia pomonella granulosis virus was subcloned and subjected to transposon mutagenesis in escherichia coli using a tn3 derivative. after screening by restriction endonuclease digestion and polymerase chain reaction (pcr), 44 clones were selected representing insertions every 100 to 300 bp. the complete sequence was compiled and the transposon insertion sites mapped precisely by sequencing. analysis of the sequence revealed the presence of 7 potential open reading frames ( ... | 1997 | 9237352 |
| expression of neuroparsin cdna in insect cells using baculovirus vectors. | the cdna encoding neuroparsin a, a polytropic neurohormone of the locust, locusta migratoria, was inserted into the genome of autographa californica nuclear polyhedrosis virus such that transcription was under control of the p10 promoter. a polypeptide having the same charge and the same apparent molecular weight as the authentic neuroparsin a and that was reactive against neuroparsin immune serum was produced in recombinant virus-infected lepidopteran cell lines but not in control virus-infecte ... | 1997 | 9243790 |
| regulation of infected-cell-specific protein synthesis in sf iplb-21 cells productively infected with spodoptera frugiperda multicapsid nuclear polyhedrosis virus. | in spodoptera frugiperda (sf iplb-21) cells productively infected with s. frugiperda multicapsid nuclear polyhedrosis virus (sfmnpv), we observed the synthesis of infected-cell-specific polypeptides (icsps) using the protein synthesis inhibitor cycloheximide (cx) and the dan synthesis inhibitor cytosine arabinoside (ara-c) in an attempt to assess whether a temporal cascade and viral dna synthesis are involved in the gene expression program of sfmnpv. inhibition of protein synthesis with cx at 0 ... | 1997 | 9268770 |
| a nuclear polyhedrosis virus from the obliquebanded leafroller, choristoneura rosaceana (harris) (lepidoptera:tortricidae). | a nuclear polyhedrosis virus (crmnpv) has been isolated from larvae of the obliquebanded leafroller choristoneura rosaceana (harris) collected near st. quentin in northwest new brunswick, canada. restriction endonuclease digestion-gel electrophoresis of this virus, using a number of different endonucleases and whole crmnpv genome southern hybridization, have shown it to be different but similar to the equivalent virus from the spruce budworm choristoneura fumiferana (clem.) (cfmnpv). the polyhed ... | 1997 | 9281399 |
| ingestion time does not influence the susceptibility of trichoplusia ni to a nuclear polyhedrosis virus | | 1997 | 9281407 |
| baculovirus expression of a human g2-specific, neutralizing igg monoclonal antibody to puumala virus. | we amplified by polymerase chain reaction the heavy- and light-chain antibody genes of a human hybridoma secreting a neutralizing, igg monoclonal antibody to the g2 protein of puumala virus. the heavy- and light-chain genes were cloned and sequenced and the deduced amino acids were aligned with those of other human antibodies to identify the constant and variable regions. the genes were cloned into the baculovirus plasmid transfer vector pacuw51 such that the heavy-chain and light-chain genes we ... | 1997 | 9281505 |
| stable transformation of insect cells to coexpress a rapidly selectable marker gene and an inhibitor of apoptosis. | we have constructed several plasmid expression vectors to express foreign genes in stably transformed insect cells. unlike baculovirus-based expression vectors by which genes of interest are expressed transiently before lysis of the virus-infected cells, genes can be expressed continuously over many passages in a stable cell line. furthermore, the function of a gene or genes expressed in a stable cell line from an insect-specific promoter that is constitutively expressed can be studied in the ab ... | 1997 | 9282319 |
| splicing is required for transactivation by the immediate early gene 1 of the lymantria dispar multinucleocapsid nuclear polyhedrosis virus. | a region of the lymantria disper multinucleocapsid nuclear polyhedrosis virus (ldmnpv) genome containing the homolog of the baculovirus ie-1 gene was identified using a series of overlapping cosmids and individual plasmids in a transient transcriptional expression assay. sequence analysis of the active region identified two orfs, one of which is 32% identical to acmnpv orf141 (ie-0) and contains a putative splice donor site and the other of which is 29% identical to acmnpv ie-1 and contains a hi ... | 1997 | 9300047 |
| characterization of the polyhedrin gene of spodoptera litura nuclear polyhedrosis virus. | the polyhedrin gene (polh) of a characteristically distinct spodoptera litura nuclear polyhedrosis virus isolate (simnpv) is identified in the hindiii-f fragment of the viral dna. the nucleotide sequence of the 1057 base pair (bp) region of this fragment contains an open reading frame (orf) without any intervening sequence for coding a polypeptide of 246 amino acids. analysis of the nucleotide sequence and deduced amino acid sequence indicate that this has more than 70% sequence identity to know ... | 1997 | 9311561 |
| baculovirus gp64 gene expression: negative regulation by a minicistron. | small upstream open reading frames (orfs) or minicistrons located in the 5' leader of eukaryotic mrnas have been shown to play a role in translational regulation of some eukaryotic genes, particularly mammalian proto-oncogenes. a survey of the baculovirus autographa californica multicapsid nuclear polyhedrosis virus genome suggests that at least 10 transcripts from late genes contain potential minicistrons, and at least three of these minicistrons appear to be conserved in homologous genes of th ... | 1997 | 9311824 |
| expression of the autographa californica nuclear polyhedrosis virus apoptotic suppressor gene p35 in nonpermissive spodoptera littoralis cells. | apoptosis was postulated as the main barrier to replication of the autographa californica nuclear polyhedrosis virus (acmnpv) in a spodoptera littoralis sl2 cell line (n. chejanovsky and e. gershburg, virology 209:519-525, 1995). thus, we hypothesized that the viral apoptotic suppressor gene p35 is either poorly expressed or nonfunctional in acmnpv-infected sl2 cells. these questions were addressed by first determining the steady-state levels of the p35 product, p35, in acmnpv-infected sl2 cells ... | 1997 | 9311840 |
| responses of insect cells to baculovirus infection: protein synthesis shutdown and apoptosis. | protein synthesis is globally shut down at late times postinfection in the baculovirus autographa californica m nuclear polyhedrosis virus (acmnpv)-infected gypsy moth cell line ld652y. a single gene, hrf-1, from another baculovirus, lymantria dispar m nucleopolyhedrovirus, is able to preclude protein synthesis shutdown and ensure production of acmnpv progeny in ld652y cells (s. m. thiem, x. du, m. e. quentin, and m. m. berner, j. virol. 70:2221-2229, 1996; x. du and s. m. thiem, virology 227:42 ... | 1997 | 9311875 |
| identification of the early actin-rearrangement-inducing factor gene, arif-1, from autographa californica multicapsid nuclear polyhedrosis virus. | in response to autographa californica multicapsid nuclear polyhedrosis virus (acmnpv) infection, a sequential rearrangement of the actin cytoskeleton occurs. previous studies suggest that the penetration of nucleocapsids induces early actin cables followed by further changes of the actin cytoskeleton which depend on early viral gene expression. by transfection of a plasmid library into trichoplusia ni tn-368 cells, we have identified an early viral gene, designated arif-1, that is able to induce ... | 1997 | 9311884 |
| baculoviral display of the green fluorescent protein and rubella virus envelope proteins. | the ability to display heterologous proteins and peptides on the surface of different types of bacteriophage has proven extremely useful in protein structure/function studies. to display such proteins in a eucaryotic environment, we have produced a vector allowing for fusion of proteins to the amino-terminus of the autographa californica nuclear polyhedrosis virus (acnpv) major envelope glycoprotein, gp64. such fusion proteins incorporate into the baculoviral virion and display the flag epitope ... | 1997 | 9325155 |
| molecular analysis of an enhancin gene in the lymantria dispar nuclear polyhedrosis virus. | a lymantria dispar nuclear polyhedrosis virus (ldmnpv) gene has been identified that encodes a homolog to the granulovirus (gv) enhancin proteins that are capable of enhancing the infection of other baculoviruses. enhancin genes have been identified and sequenced for three species of gvs but have not been found in any other nuclear polyhedrosis virus to date. the ldmnpv enhancin gene is located between 67.6 and 70.1 kbp on the viral genome. northern and primer extension analyses of viral rnas in ... | 1997 | 9343163 |
| infectivity and effects of gypsy moth and spruce budworm nuclear polyhedrosis viruses ingested by rainbow trout. | rainbow trout fingerlings were fed dried krill injected with gypsy moth or spruce budworm nuclear polyhedrosis virus (ldnpv and cfnpv, respectively) at a total dose of 1.4 x 10(7) occlusion bodies (obs) per fish. by the end of the 21-day experimental period there were no adverse effects on fish survival or behavior and no significant differences in feeding rates or growth between treated and control fish. the internal organs of all fish were examined at the end of the experiment and there were n ... | 1997 | 9352215 |
| production of recombinant herpes simplex virus protease in 10-l stirred vessels using a baculovirus-insect cell expression system. | a gene expression system using recombinant autographa california nuclear polyhedrosis virus (baculovirus) and sf-9 cells has been scaled up to the 10-l tank level and shown to be capable of producing herpes simplex virus (hsv) protease in serum-free media. high densities of spodoptera frugiperda (sf-9) cells were achieved by modifying two 10-l biolafitte fermenters specifically for insect cell growth. the existing rushton impellers were replaced by marine impellers to reduce shear and the aerati ... | 1997 | 9366090 |
| dna-dependent transregulation by ie1 of autographa californica nuclear polyhedrosis virus: ie1 domains required for transactivation and dna binding. | ie1 is the principal early transregulator of autographa californica multicapsid nuclear polyhedrosis virus (acmnpv). the 582-residue protein stimulates viral transcription and binds as a dimer to 28-bp palindromic repeats (28-mers) comprising the acmnpv homologous region (hr) transcription enhancers. to define ie1 domains responsible for hr-dependent transactivation, we first constructed a series of ie1 fusions to the dna binding domain of the yeast gal4 transactivator. in transfection assays, g ... | 1997 | 9371585 |
| identification of two independent transcriptional activation domains in the autographa californica multicapsid nuclear polyhedrosis virus ie1 protein. | the autographa californica multicapsid nuclear polyhedrosis virus immediate-early protein, ie1, is a 582-amino-acid phosphoprotein that regulates the transcription of early viral genes. deletion of n-terminal regions of ie1 in previous studies (g. r. kovacs, j. choi, l. a. guarino, and m. d. summers, j. virol. 66:7429-7437, 1992) resulted in the loss of transcriptional activation, suggesting that this region may contain an acidic activation domain. to identify independently functional transcript ... | 1997 | 9371622 |
| interactions of recombinant and wild-type baculoviruses with classical insecticides and pyrethroid-resistant tobacco budworm (lepidoptera: noctuidae). | in tests with neonate heliothis virescens (f.), we characterized interactions of all combinations of a recombinant autographa californica (speyer) nuclear polyhedrosis virus (acaait) that expresses an insect-selective neurotoxin (aait) and wild-type acnpv when combined with low concentrations of several conventional insecticides. all combinations of the recombinant virus acaait and insecticides showed a positive interaction (decrease in the median lethal time (lt50) compared with the lt50 for ei ... | 1997 | 9374595 |
| characterization of the replication cycle of the lymantria dispar nuclear polyhedrosis virus. | the life cycle of the lymantria dispar nuclear polyhedrosis virus (ldmnpv) was characterized through analysis of budded virus (bv) release, the temporal formation of polyhedra, the temporal transcription pattern of representative early, late, and hyper-expressed late genes, and the onset of dna replication in the ld652y cell line. transcripts from the ldmnpv immediate early gene g22 were detected 4 h post infection (h p.i.). the late and hyper-expressed late p39 capsid and polyhedrin genes were ... | 1997 | 9381798 |
| a baculovirus (bombyx mori nuclear polyhedrosis virus) repeat element functions as a powerful constitutive enhancer in transfected insect cells. | it has been previously reported that baculovirus homologous regions, the regions of baculovirus genomes that contain the origins of dna replication, can augment the expression of a small number of baculovirus genes in vitro. we are now reporting that a region of the genome of bombyx mori nuclear polyhedrosis virus (bmnpv) containing the homologous region 3 (hr3) acts as an enhancer for the promoter of a nonviral gene, the cytoplasmic actin gene of the silkmoth b. mori. incorporation of the hr3 s ... | 1997 | 9388209 |
| efficient protein production using a bombyx mori nuclear polyhedrosis virus lacking the cysteine proteinase gene. | infection by a baculovirus (bombyx mori nuclear polyhedrosis virus, bmnpv) in silkworm (bombyx mori) larvae is highly efficient as an expression system for the production of useful proteins. however, the amount of the protein of interest expressed tends to decrease in the later stages of infection presumably due, in part, to a proteinase produced in the larval haemolymph. the n-terminal amino acid sequence of a proteinase purified from the haemolymph of bmnpv-infected larvae was identical to the ... | 1997 | 9400955 |
| expression of human immunodeficiency virus genes using baculovirus expression system. | the structural protein genes of hiv-1 and hiv-2 have been expressed in spodoptera frugiperda (sf) cells using baculovirus expression system. the noncoding flanking sequences of hiv structural genes were removed and a putative ribosome binding site was placed in front of the open reading frame of each gene by using crossover linker mutagenesis. the coding sequences of the gag, pol, env, and vif proteins were inserted into autographa californica nuclear polyhedrosis virus (acnpv) so that hiv genes ... | 1997 | 9406188 |
| role of baculovirus ie2 and its ring finger in cell cycle arrest. | the ie2 gene of autographa californica nuclear polyhedrosis virus (acmnpv) is known to transactivate transient expression from viral promoters in a host cell-specific manner. we report that transfection of spodoptera frugiperda (sf-21) cells with ie2 was sufficient to arrest the cell cycle, resulting in the accumulation of enlarged cells with abnormally high dna contents. by 72 h posttransfection, more than 50% of ie2-transfected cells had dna contents greater than 4n. there was no evidence of m ... | 1998 | 9420274 |
| expression, purification, and characterization of a soluble form of human cytomegalovirus glycoprotein b. | the human cytomegalovirus glycoprotein b gene (gb; gpul55) was truncated at amino acid 692 and recombined into autographa californica nuclear polyhedrosis virus (baculovirus). infection of insect cells with the recombinant baculovirus resulted in high-level expression and secretion of the truncated gb protein (gb-s) into the culture medium. purification of gb-s by monoclonal antibody affinity chromatography yielded a protein of ca. 200 kda. characterization of the 200-kda purification product in ... | 1997 | 9426459 |
| autographa californica nuclear polyhedrosis virus: subcellular localization and protein trafficking of bv/odv-e26 to intranuclear membranes and viral envelopes. | the autographa californica nuclear polyhedrosis virus da26 gene codes for an envelope protein of both budded virus (bv) and occlusion derived virus (odv). western blot and temporal analysis of infected cell extracts detected a protein of 26 kda by 4 h postinfection (p.i.). the amount of protein increased by 16 h p.i. and remained at high levels throughout infection. by 36 h p.i. several additional immunoreactive proteins were detected which migrated at approximately 18 kda and remained through 9 ... | 1998 | 9448690 |
| identification and characterization of a protein kinase-interacting protein encoded by the autographa californica nuclear polyhedrosis virus. | we have used a yeast two-hybrid system to identify a baculoviral gene encoding a protein kinase-interacting protein (pkip). the pkip gene is located at 15.8-16.2 m.u (map units) and represents orf 24 in the sequence of ayres et al. (1994) of the autographa californica nuclear polyhedrosis virus. pkip is a 19.2-kda protein and appears to stimulate the activity of the viral protein kinase-1 in vitro. northern blotting analysis revealed that pkip is a late gene. attempts to plaque purify a pkip- vi ... | 1998 | 9454690 |
| characterization of recombinant autographa californica nuclear polyhedrosis virus (npv) expressing the beta-galactosidase gene in both sf21 and bm5 cells by bombyx mori npv p143 helicase gene. | genomic dna of recombinant acnpv expressing beta-galactosidase was cotransfected with p143 helicase gene of bmnpv into sf21 cells. ac-bm hybrid viruses capable of replicating in both bm5 and sf21 cells were isolated. ac-bm hybrid viruses expressing beta-galactosidase either at the highest (ac-bm hybrid virus-he) or lowest (ac-bm hybrid virus-le) level were chosen for the characterization of beta-galactosidase expression in bm5 and sf21 cells. expression level of beta-galactosidase and replicatio ... | 1997 | 9509418 |
| in vitro transcription of pe38/polyhedrin hybrid promoters reveals sequences essential for recognition by the baculovirus-induced rna polymerase and for the strength of very late viral promoters. | in vitro transcription was used to analyze the promoter specificity of the alpha-amanitin-resistant rna polymerase that is induced late during infection of autographa californica multicapsid nuclear polyhedrosis virus. by modifying the preparation of crude nuclear extracts, we have established an assay that permits differentiation between weak late and strong very late viral promoters. the virus-induced rna polymerase initiates at a taag sequence motif in both late and very late promoters. based ... | 1998 | 9525621 |
| species-specificity in endoplasmic reticulum signal peptide utilization revealed by proteins from trypanosoma brucei and leishmania. | n-terminal signal peptides direct secretory and most membrane proteins into the exocytic pathway at the endoplasmic reticulum. signal sequences can function across kingdoms. however, our attempts at translocating variant surface glycoprotein (vsg) 117, vsg mvat7, vsg 221 and bip from trypanosoma brucei and gp63 from leishmania chagasi into canine pancreas microsomes failed. on replacing the signal peptide of vsg 117 with that from yeast prepro-alpha-mating factor (ppalphamf) the chimaeric protei ... | 1998 | 9531493 |
| development and validation of a competitive enzyme-linked immunosorbent assay for detection of type a influenza antibodies in avian sera. | serologic screening of avian sera for group-specific antibodies to type a influenza is currently accomplished by using the avian influenza (ai) agar gel immunodiffusion (agid) test. a competitive enzyme-linked immunosorbent assay (celisa) was developed using a baculovirus vector, autographa californica nuclear polyhedrosis virus, expressing the nucleoprotein (np) gene of a/ann arbor/6/60 influenza virus. the recombinant np was obtained by inoculation of spodoptera frugiperda (sf9) insect cells o ... | 1998 | 9533078 |
| characterization of a nuclear polyhedrosis virus of spodoptera frugiperda from argentina. | | 1998 | 9538035 |
| new isolate of macosoma neustria nuclear polyhedrosis virus in latvia. | | 1998 | 9538036 |
| in vitro and in vivo host range of anticarsia gemmatalis multiple nuclear polyhedrosis virus. | a clone of the wild type (wt) anticarsia gemmatalis multiple nuclear polyhedrosis virus agmnpv, derived from a geographical isolate (hondrina, brazil) and designated agmnpv-cl4-3a1, was used to determine the host range of this virus in six established lepidopteran cell lines: anticarsia gemmatalis (bcirl-ag-am1), helicoverpa zea (bcirl-hz-am1), heliothis virescens (bcirl-hv-am1), helicoverpa armigera (bcirl-ha-am1), trichoplusia ni (tn-cl1), bombyx mori (bmn), and a coleopteran cell line anthono ... | 1998 | 9542640 |
| removal of 106 amino acids from the n-terminus of udp-glcnac: alpha-3-d-mannoside beta-1,2-n-acetylglucosaminyltransferase i does not inactivate the enzyme. | udp-glcnac: alpha-3-d-mannoside beta-1,2-n-acetylglucosaminyltransferase i (gnti, ec 2.4.1.101) plays an essential role in the conversion of oligomannose to complex and hybrid n-glycans. rabbit gnti is 447 residues long and has a short four-residue n-terminal cytoplasmic tail, a 25-residue putative signal-anchor hydrophobic domain, a stem region of undetermined length and a large c-terminal catalytic domain, a structure typical of all glycosyltransferases cloned to date. comparison of the amino ... | 1998 | 9557881 |
| expression of fas-fas ligand system associated with atresia in murine ovary. | we detected that fas receptor (fas) was expressed at transcriptional levels in oocytes/eggs and some granulosa cells of murine ovary, whereas, fas ligand (fasl) was found to be strongly expressed in granulosa cells by means of in situ hybridisation. these results were supported by an indirect immunofluorescence (iif) test with anti-fas monoclonal antibody (mab)/fasl ab. the lysates from granulosa cells were precipitated by anti-fasl ab, exhibiting a specific band at 40 kda. when zona pellucida ( ... | 1997 | 9563680 |
| the p95 gene of bombyx mori nuclear polyhedrosis virus: temporal expression and functional properties. | as part of our effort to identify baculovirus proteins acting as transcriptional regulators, we have characterized a gene, p95, of bombyx mori nuclear polyhedrosis virus (bmnpv) that encompasses an open reading frame for a putative 95-kda polypeptide (p95). the n-terminal half of the conceptually translated p95 contains two zinc finger-type dna-binding motifs, and its c terminus contains a proline-rich region reminiscent of transcriptional activation regions. northern blot analysis indicates tha ... | 1998 | 9573244 |
| autographa californica nucleopolyhedrovirus infection results in sf9 cell cycle arrest at g2/m phase. | baculovirus infection results in the induction of membrane structures within the nucleoplasm of the host cells. the source of these membranes is unclear; however, using the normal dynamics of cellular membranes and the nuclear envelope as a model, it is possible that the cell cycle might play a role in the regulation of formation of these intranuclear membranes. therefore, one goal of this study was to investigate the effect of baculovirus infection on the cell cycle of sf9 host cells. since few ... | 1998 | 9581791 |
| mapping of orf121, a factor that activates baculovirus early gene expression. | the protein product of the 39k gene of autographa californica nuclear polyhedrosis virus is thought to be important for viral replication because of its association with the virogenic stroma and its role in activation of late gene expression transient expression assays showed that addition of a dna fragment encoding a 58-amino-acid polypeptide increased expression of a 39k reporter plasmid. this stimulation was dependent on cotransfection of a plasmid encoding ie1. cotransfection of this gene, o ... | 1998 | 9601517 |
| expression and mutational analysis of the baculovirus very late factor 1 (vlf-1) gene. | we have examined the expression and function of a gene, vlf-1, of autographa californica nuclear polyhedrosis virus that is known to encode a regulator of very late gene transcription. western blot analysis revealed that vlf-1 is expressed during the late phase of infection, primarily from 15 to 24 h postinfection. vlf-1 localized in the cell nucleus and was also present in the nucleocapsids of virus particles. mapping of vlf-1 mrna by primer extension showed that transcription initiates at a ta ... | 1998 | 9614871 |
| effects of substituting granulin or a granulin-polyhedrin chimera for polyhedrin on virion occlusion and polyhedral morphology in autographa californica multinucleocapsid nuclear polyhedrosis virus. | substitution of granulin from the trichoplusia ni granulosis virus (tngv) for polyhedrin of the autographa californica multinucleocapsid nuclear polyhedrosis virus (acmnpv) yielded a few very large (2 to 5 micron) cuboidal inclusions in the cytoplasm and nucleus of infected cells. these polyhedra lacked the beveled edges characteristic of wild-type acmnpv polyhedra, contained fractures, and occluded few virions. placing a nuclear localization signal (krkk) in granulin directed more granulin to t ... | 1998 | 9621097 |
| the in vivo production of spodoptera littoralis nuclear polyhedrosis virus. | the in vivo production of the nucleopolyhedrovirus (npv) of the egyptian cotton leafworm spodoptera littoralis was studied experimentally. larvae (7 days old) of 30-50 mg were experimentally infected with a range of npv doses then harvested alive at various times after dosing to determine the effect of dose and incubation time on npv productivity. maximum npv production achieved after 7 days incubation was 1.86 x 10(9) polyhedral inclusion bodies (pibs) per larvae using an inoculum of 1 x 10(4) ... | 1998 | 9628227 |
| a hybrid baculovirus-bacteriophage t7 transient expression system. | a hybrid recombinant baculovirus-bacteriophage t7 expression system was developed for transient expression in insect cells of plasmids with foreign genes provided with a t7 promoter. the coding sequence for t7 rna polymerase, with or without a nuclear localization signal, was inserted into the genome of autographa californica nuclear polyhedrosis virus. recombinant viruses stably expressed t7 rna polymerase in insect cells. upon transfection of infected insect cells with plasmids containing the ... | 1995 | 9634768 |
| transovarian transmission of a foreign gene in the silkworm, bombyx mori, by autographa californica nuclear polyhedrosis virus. | we introduced a firefly luciferase gene, expressed under control of drosophila heat shock protein gene promoter, into autographa californica nuclear polyhedrosis virus (acnpv). when the 5th instar larvae of the silkworm, bombyx mori, were inoculated with the recombinant virus, luciferase activities were detected in the virus-infected larvae and pupae, and in the newly hatched larvae of the next generation. pcr amplification and southern blot hybridization analysis demonstrated that the luciferas ... | 1995 | 9636278 |
| eukaryotic virus display: engineering the major surface glycoprotein of the autographa californica nuclear polyhedrosis virus (acnpv) for the presentation of foreign proteins on the virus surface. | we describe the development of the baculovirus autographa californica nuclear polyhedrosis virus (acnpv) as a vector for the display of distinct proteins on the viral surface in a manner that is analogous to the established bacterial "phage display" systems. as a model system, the marker gene encoding the 26kda protein glutathione-s-transferase (gst) was used to construct several fusions with the major baculovirus glycoprotein gp64 gene. following expression in spodoptera frugiperda (sf9) cells, ... | 1995 | 9636281 |
| identification of a novel lymantria dispar nucleopolyhedrovirus mutant that exhibits abnormal polyhedron formation and virion occlusion. | in previous studies on the formation of lymantria dispar nuclear polyhedrosis virus (ldmnpv) few polyhedra (fp) mutants, several polyhedron formation mutants (pfm) were identified that appeared to be unique. these viral mutants are being characterized to investigate the processes of polyhedron formation and virion occlusion. ldmnpv isolate pfm-1 is one of these mutants, and is described in this report. genetic techniques were used to determine if isolate pfm-1 contained a mutation in the polyhed ... | 1998 | 9647698 |
| observations on the presence of the peritrophic membrane in larval trichoplusia ni and its role in limiting baculovirus infection. | light microscopical examinations of dissected and stained peritrophic membranes (pms) were conducted to determine the presence or absence of this protective structure in larvae of trichoplusia ni, prior to and through ecdysis. observations of fourth- and fifth-instar larvae of t. ni from two independent rearing colonies showed that pms were present and lined the midgut prior to, during, and immediately after ecdysis in both instars. western blot analysis of insect intestinal mucin (iim), a major ... | 1998 | 9647702 |
| detection of a virus enhancing factor in the spheroid, spindle, and virion of an entomopoxvirus. | spheroids, spindles, and virions of an entomopoxvirus (epv) enhanced the infectivity of a nuclear polyhedrosis virus (npv) when they were perorally administered to larvae of the armyworm, pseudaletia separata. spheroids and spindles at the same dose exhibited nearly the same enhancing activity. when the dose of spheroids or spindles was reduced 10 times, the median infectious dose of the npv was increased approximately 100 times. an antiserum against an enhancing factor detected the homologous a ... | 1998 | 9647705 |
| expression of biologically active recombinant porcine gm-csf by baculovirus gene expression system. | the full length porcine granulocyte/macrophage colony stimulating factor (gm-csf) cdna, including secretion signal peptide coding region was recloned into baculovirus transfer vector pacym1. the vector was then transfected with autographica californica nuclear polyhedrosis virus (acnpv) dna into sf21ae cells and the recombinant virus acpgm was recovered. recombinant porcine gm-csf (rpgm-csf) was obtained from the serum-free culture medium of tn5 cells infected with the acpgm virus, and was shown ... | 1998 | 9682962 |
| a baculovirus single-stranded dna binding protein, lef-3, mediates the nuclear localization of the putative helicase p143. | the intracellular localization of the baculovirus autographa californica nuclear polyhedrosis virus p143 gene product (p143) was investigated by immunofluoresence staining of infected and transfected cells. as expected for a protein essential for viral dna replication, under these conditions, p143 was localized to the nucleus. however, when a plasmid directing the synthesis of p143 from its own promoter was co-transfected with a plasmid expressing ie-1, p143 was found in the cytoplasm. cotransfe ... | 1998 | 9683569 |
| characterization of a baculovirus-encoded rna 5'-triphosphatase. | autographa californica nuclear polyhedrosis virus (acnpv) encodes a 168-amino-acid polypeptide that contains the signature motif of the superfamily of protein phosphatases that act via a covalent cysteinyl phosphate intermediate. the sequence of the acnpv phosphatase is similar to that of the rna triphosphatase domain of the metazoan cellular mrna capping enzyme. here, we show that the purified recombinant acnpv protein is an rna 5'-triphosphatase that hydrolyzes the gamma-phosphate of triphosph ... | 1998 | 9696798 |
| control of baculovirus polyhedrin gene expression by very late factor 1. | vlf-1 is a baculovirus gene that regulates very late gene expression (j. r. mclachlin and l. k. miller, j. virol., 68, 7746-7756, 1994) and also plays a crucial role in the replication of the budded form of autographa californica nuclear polyhedrosis virus (acmnpv) (s. yang and l. k. miller, "expression and mutational analysis of the baculovirus very late factor 1 (vlf-1) gene." virology, 245, 99-109, 1998). to examine the influence of vlf-1 expression on baculovirus infection, we constructed re ... | 1998 | 9705262 |
| a protein tyrosine phosphatase-like protein from baculovirus has rna 5'-triphosphatase and diphosphatase activities. | the superfamily of protein tyrosine phosphatases (ptps) includes at least one enzyme with an rna substrate. we recently showed that the rna triphosphatase domain of the caenorhabditis elegans mrna capping enzyme is related to the ptp enzyme family by sequence similarity and mechanism. the ptp most similar in sequence to the capping enzyme triphosphatase is bvp, a dual-specificity ptp encoded by the autographa californica nuclear polyhedrosis virus. although bvp previously has been shown to have ... | 1998 | 9707557 |
| interactions between a nosema sp. (microspora: nosematidae) and nuclear polyhedrosis virus infecting the gypsy moth, lymantria dispar (lepidoptera: lymantriidae). | simultaneous and sequential per os inoculations of gypsy moth larvae with the lymantria dispar nuclear polyhedrosis virus (ldnpv) and a nosema sp. from portugal demonstrated that the interaction of two pathogens during coinfection was variable, ranging from synergistic to antagonistic. susceptibility of gypsy moth larvae to viral infection was unaffected by simultaneous and subsequent microsporidian infection. this resulted from the comparatively slow pathogenesis of the microsporidium when comp ... | 1998 | 9709015 |
| a virus-encoded rna polymerase purified from baculovirus-infected cells. | a dna-dependent rna polymerase was purified to homogeneity, starting from insect cells infected with the baculovirus autographa californica nuclear polyhedrosis virus (acnpv). the purified polymerase supported accurate and specific transcription from late and very late promoters but was not active on viral early promoters. thus, promoter recognition is an integral function of the purified enzyme. the purified rna polymerase was composed of only four equimolar subunits, which makes it the simples ... | 1998 | 9733837 |
| colourimetric pcr-based detection of monodon baculovirus in whole penaeus monodon postlarvae. | the development of a nested polymerase chain reaction (pcr) assay is described to detect low concentrations of monodon baculovirus (mbv) dna from total penaeus monodon postlarval dna. a modified dna extraction procedure was also developed to circumvent problems associated with co-purification of pcr inhibitors in total dna extracted from whole postlarvae. this method involved mechanical disruption of frozen prawn material immediately followed by phenol extraction at high temperature. an assessme ... | 1998 | 9763125 |
| persistent baculovirus infection results from deletion of the apoptotic suppressor gene p35. | infection with the wild-type baculovirus autographa californica multiple nuclear polyhedrosis virus (acmnpv) results in complete death of spodoptera frugiperda (sf) cells. however, infection of sf cells with acmnpv carrying a mutation or deletion of the apoptotic suppressor gene p35 allowed the cloning of surviving sf cells that harbored persistent viral genomes. persistent infection established with the virus with p35 mutated or deleted was blocked by stable transfection of p35 in the host geno ... | 1998 | 9765462 |
| the early baculovirus he65 promoter: on the mechanism of transcriptional activation by ie1. | we have initiated studies on the mechanism of early transcriptional activation of the early he65 promoter during infection with autographa californica multicapsid nuclear polyhedrosis virus. this analysis is based on a comparison of the sequences required for he65 promoter activation with those sequences that support specific protein binding. the he65 promoter is located immediately downstream of the homologous region (hr) 4a. the sequences of hr4a are characterized by two imperfect palindromes ... | 1998 | 9791025 |