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[comparative study of aerosol and oral methods of infection of lympantria dispar l. caterpillars with nuclear polyhedrosis virus].the aerosol and oral routes of infection of gypsy moth larvae with nuclear polyhedrosis virus are compared. the virus in aerosol retains its biological activity. the virus output/expenditure ratio is virtually the same in the studied routes of infection. aerosol method of inoculation saves 30% components of media and is 6-8 times less labor consuming. this method permits complete automation of infection of larvae, thus essentially improving the efficacy of baculovirus production.199910500990
expression of the fusion protein recombinant human granulocyte-macrophage colony stimulating factor and leukemia inhibitory factor in a baculovirus vector system.a fusion gene coding human granulocyte-macrophage colony stimulating factor (gm-csf) and leukemia inhibitory factor (lif) cdnas was inserted into the transfer vector psxivvi+ x3 with the control of syn and xiv promoters. the sf9 cells (spodoptera frugiperda) were co-transfected with the recombinant plasmid and tnnpv dna (trichoplusia ni nuclear polyhedrosis virus dna). the fusion protein recombinant human granulocyte-macrophage colony stimulating factor (gm-csf) and leukemia inhibitory factor (l ...199910510487
detection of baculovirus-infected insect cells by flow cytometric side-scatter analyses.the baculovirus expression vector system (bevs), utilizing the autographa californica nuclear polyhedrosis virus (acnpv), has turned out to be an attractive alternative for high-level expression (<600 mg/l) of recombinant proteins. however, there is a shortage of reliable methods for monitoring the infection process in situations where marker proteins cannot be used.199910520205
expression of genes coding for animal virus glycoproteins in heterologous systems.the outermost layers of animal viruses are usually composed of glycoproteins. they are responsible not only for the entrance of viruses into, and release from host cells but also for the initial interaction of a viral particle with immunological defense of the host. it is therefore not surprising that many laboratories devote a lot of effort to study viral glycoproteins at the molecular level. very often such studies are possible only after the introduction of a glycoprotein gene into a heterolo ...199910547034
baculovirus-based genetic screen for antiapoptotic genes identifies a novel iap.the prototype baculovirus, autographa californica multiple nuclear polyhedrosis virus (acmnpv) expresses p35, a potent anti cell-death gene that promotes the propagation of the virus by blocking host cell apoptosis. infection of insect sf-21 cells with acmnpv lacking p35 induces apoptosis. we have used this pro-apoptotic property of the p35 null virus to screen for genes encoding inhibitors of apoptosis that rescue cells infected with the p35 defective virus. we report here the identification of ...199910593985
human interleukin-2 production in insect (trichoplusia ni) larvae: effects and partial control of proteolysis.many eukaryotic proteins have been successfully expressed in insect cells infected with a baculovirus in which the foreign gene has been placed under the control of a viral promoter. this system can be costly at large scale due to the quality of virus stock, problems of oxygen transfer, and severity of large-scale contamination. to circumvent this problem, we have investigated the expression of a foreign protein, human interleukin-2 (il-2), in insect larvae, trichoplusia ni, infected with the ba ...199910099527
purification of human interleukin-2 fusion protein produced in insect larvae is facilitated by fusion with green fluorescent protein and metal affinity ligand.the fusion protein of green fluorescent protein (gfp) and human interleukin-2 (hil-2) was produced in insect trichoplusia ni larvae infected with recombinant baculovirus derived from the autographa californica nuclear polyhedrosis virus (acnpv). this fusion protein was composed of a metal ion binding site (his)6 for rapid one-step purification using immobilized metal affinity chromatography (imac), uv-optimized gfp (gfpuv), enterokinase cleavage site for recovering hil-2 from purified fusion pro ...199910194406
expression and purification of human interleukin-2 simplified as a fusion with green fluorescent protein in suspended sf-9 insect cells.a fusion protein of human interleukin-2 (hil-2) and green fluorescent protein (gfp) was expressed in insect sf-9 cells infected with recombinant baculovirus derived from the autographa californica nuclear polyhedrosis virus (acnpv). this fusion protein was comprised of a histidine affinity ligand for simplified purification using immobilized metal affinity chromatography (imac), uv-optimized gfp (gfpuv) as a marker, an enterokinase cleavage site for recovery of hil-2 from the fusion, and the mod ...199910201111
use of the baculovirus system to assemble polyomavirus capsid-like particles with different polyomavirus structural proteins: analysis of the recombinant assembled capsid-like particles.the genes encoding the structural proteins (vp1, vp2 and vp3) of murine polyomavirus were cloned into the p2bac dual multiple cloning site vector, individually or jointly, and the corresponding proteins were expressed in spodoptera frugiperda (sf9) insect cells by cotransfecting sf9 cells with the constructed vector and the linear dna of autographa californica multiple nuclear polyhedrosis virus (acmnpv). recombinant capsid-like particles could be purified 5 days post-infection from sf9 cells in ...199910211971
a field release of genetically engineered gypsy moth (lymantria dispar l.) nuclear polyhedrosis virus (ldnpv).the gypsy moth (lymantria dispar l.) nuclear polyhedrosis virus was genetically engineered for nonpersistence by removal of the gene coding for polyhedrin production and stabilized using a coocclusion process. a beta-galactosidase marker gene was inserted into the genetically engineered virus (ldgev) so that infected larvae could be tested for its presence using a colorimetric assay. in 1993, ldgev-infected gypsy moths were released in a forested plot in massachusetts to test for spread and pers ...199910222179
autographa californica nuclear polyhedrosis virus dna polymerase: measurements of processivity and strand displacement.the dna polymerase (dnapol) of autographa californica nuclear polyhedrosis virus was purified to homogeneity from recombinant baculovirus-infected cells. dnapol was active in polymerase assays on singly primed m13 template, and full-length replicative form ii product was synthesized at equimolar ratios of enzyme to template. the purified recombinant dnapol was shown to be processive by template challenge assay. furthermore, dnapol was able to incorporate hundreds of nucleotides on an oligo(dt)-p ...199910233952
development and use of a pcr assay for detection of the reproductive virus in wild populations of helicoverpa zea (lepidoptera: noctuidae)helicoverpa zea reproductive virus (hzrv) is a nonoccluded bacilliform virus that affects both female and male moths of the corn earworm h. zea. in order to study the biology and host range of hzrv, a bioassay was previously developed to detect the presence of this virus in infected insects. a drawback of this bioassay is that it is time consuming and requires more than a month to complete. here we describe the development of a polymerase chain reaction (pcr) assay for the rapid detection of hzr ...19999878296
baculovirus p33 binds human p53 and enhances p53-mediated apoptosis.in vertebrates, p53 participates in numerous biological processes including cell cycle regulation, apoptosis, differentiation, and oncogenic transformation. when insect sf-21 cells were infected with a recombinant of the baculovirus autographa californica nuclear polyhedrosis virus (acmnpv) overexpressing human p53, p53 formed a stable complex with the product of the acmnpv orf92, a novel protein p33. the interaction between p53 and p33 was further confirmed by immunoprecipitation studies. when ...19999882325
an analysis of the role of the target membrane on the gp64-induced fusion pore.influenza hemagglutinin (ha) and gp64 of the baculovirus autographa californica multicapsid nuclear polyhedrosis virus induce strikingly different initial fusion pores when mediating fusion between host cells that express these fusion proteins and target cells (plonsky and zimmerberg, 1996; spruce et al., 1989, 1991; zimmerberg et al., 1994). however, in these experiments, variations in host and target membranes confounded the analysis of the role that major components of the fusion reaction pla ...19999887319
in vivo and in vitro analysis of baculovirus ie-2 mutants.upon transient expression in cell culture, the ie-2 gene of autographa californica nuclear polyhedrosis virus (acmnpv) displays three functions: trans activation of viral promoters, direct or indirect stimulation of virus origin-specific dna replication, and arrest of the cell cycle. the ability of ie2 to trans stimulate dna replication and coupled late gene expression is observed in a cell line derived from spodoptera frugiperda but not in a cell line derived from trichoplusia ni. this finding ...19999971831
activation of baculovirus very late promoters by interaction with very late factor 1.very late factor 1 (vlf-1) of autographa californica multicapsid nuclear polyhedrosis virus (acmnpv) activates the transcription of two genes, polyhedrin (polh) and p10, during the final, occlusion-specific phase of infection. using transient expression assays responsive to vlf-1, we identified linker scan mutations in the polh and p10 promoters which abolished or weakened the ability of the promoters to respond to stimulation by vlf-1. these mutations were located between the transcriptional an ...199910074194
optimising fed-batch production of recombinant proteins using the baculovirus expression vector system.fed-batch culture can offer significant improvement in recombinant protein production compared to batch culture in the baculovirus expression vector system (bevs), as shown by nguyen et al. (1993) and bedard et al. (1994) among others. however, a thorough analysis of fed-batch culture to determine its limits in improving recombinant protein production over batch culture has yet to be performed. in this work, this issue is addressed by the optimisation of single-addition fed-batch culture. this t ...199810099329
an efficient way to introduce unique restriction endonuclease sites into a baculovirus genome.recombinant baculoviruses which can be linearized at unique sites with restriction endonucleases can greatly facilitate the construction of other recombinants including baculovirus expression vectors and site-specific mutants. we designed a strategy to introduce unique restriction endonuclease sites at virtually any location in a baculovirus genome. the unique sites were first introduced onto a transfer plasmid which also contained in the vector portion of the plasmid an e. coli lacz gene and a ...19989923739
a novel expression system based on host-range expansion of baculovirus.a host range expanded recombinant autographa californica multiple-nucleocapsid nucleopolyhedrosis virus acmnpv/r2 was obtained by cotransfection of the bacmid dna from escherichia coli dh10bac along with a plasmid pbmh-m containing hindiii m fragment of bombyx mori nuclear polyhedrosis virus (bmnpv) genomic dna. a recombinant transposon vector carrying a mutant green fluorescent protein gene (gfp) and a polyhedrin gene was constructed. transposition was carried out in both e. coli dh10bac and e. ...19989923744
molecular characterization, enzymatic analysis, and purification of murine proprotein convertase-1/3 (pc1/pc3) secreted from recombinant baculovirus-infected insect cells.a cdna coding for the murine proprotein convertase-1 (mpc1 also known as mpc3 or mspc3) was inserted into the autographa californica nuclear polyhedrosis virus. following infection of spodoptera frugiperda cells, the recombinant n-glycosylated protein is secreted into the cell culture medium from which it can be purified to homogeneity as a fully enzymatically active enzyme. two major secreted molecular forms of mpc1 with apparent molecular weights of 85 and 71 kda, respectively, and a minor one ...19989882569
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 ...19989448690
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 ...19989454690
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 ...19989573244
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 ...19989581791
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 ...19989601517
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 ...19989614871
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 ...19989621097
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) ...19989628227
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 ...19989647698
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 ...19989647702
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 ...19989647705
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 ...19989682962
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 ...19989683569
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 ...19989696798
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 ...19989705262
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 ...19989707557
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 ...19989709015
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 ...19989733837
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 ...19989763125
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 ...19989765462
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 ...19989791025
guanylyltransferase activity of the lef-4 subunit of baculovirus rna polymerase.the baculovirus autographa californica nuclear polyhedrosis virus encodes a dna-dependent rna polymerase that transcribes viral late genes. this polymerase is composed of four equimolar subunits, lef-4, lef-8, lef-9, and p47. here we present data indicating that the lef-4 subunit of rna polymerase is a guanylyltransferase. incubation of rna polymerase in the presence of divalent cation and radiolabeled gtp resulted in the formation of a covalent enzyme-guanylate complex that comigrated with the ...19989811738
the lef-4 subunit of baculovirus rna polymerase has rna 5'-triphosphatase and atpase activities.the baculovirus autographa californica nuclear polyhedrosis virus encodes a dna-dependent rna polymerase that is required for transcription of viral late genes. this polymerase is composed of four equimolar subunits, lef-8, lef-4, lef-9, and p47. the lef-4 subunit has guanylyltransferase activity, suggesting that baculoviruses may encode a full complement of capping enzymes. here we show that lef-4 is a bifunctional enzyme that hydrolyzes the gamma phosphates of triphosphate-terminated rna and a ...19989811739
rna 5'-triphosphatase, nucleoside triphosphatase, and guanylyltransferase activities of baculovirus lef-4 protein.autographa californica nuclear polyhedrosis virus late and very late mrnas are transcribed by an rna polymerase consisting of four virus-encoded polypeptides: lef-8, lef-9, lef-4, and p47. the 464-amino-acid lef-4 subunit contains the signature motifs of gtp:rna guanylyltransferases (capping enzymes). here, we show that the purified recombinant lef-4 protein catalyzes two reactions involved in rna cap formation. lef-4 is an rna 5'-triphosphatase that hydrolyzes the gamma phosphate of triphosphat ...19989811740
nineteen baculovirus open reading frames, including lef-12, support late gene expression.a set of 18 plasmid subclones of the autographa californica nuclear polyhedrosis virus genome, each containing an identified late expression factor gene (lef), supports expression from a late viral promoter in transient expression assays in the sf-21 cell line derived from spodoptera frugiperda. we have constructed a further set of plasmids in which each lef open reading frame (orf) is controlled by the drosophila melanogaster heat shock protein 70 (hsp70) promoter and epitope tagged. failure of ...19989811761
the potential role of a late gene expression factor, lef2, from bombyx mori nuclear polyhedrosis virus in very late gene transcription and dna replication.several late gene expression factors (lefs) have been implicated in fostering high levels of transcription from the very late gene promoters of polyhedrin and p10 from baculoviruses. we cloned and characterized from bombyx mori nuclear polyhedrosis virus a late gene expression factor (bmlef2) that encodes a 209-amino-acid protein harboring a cys-rich c-terminal domain. the temporal transcription profiles of lef2 revealed a 1.2-kb transcript in both delayed early and late periods after virus infe ...19989813207
a mutational analysis of the baculovirus inhibitor of apoptosis op-iap.a family of antiapoptotic regulators known as inhibitors of apoptosis (iaps) was initially identified and functionally described in baculoviruses, and iap homologues are now known in insects, birds, and mammals. baculovirus and drosophila iaps inhibit apoptosis induced by drosophila proapoptotic proteins reaper, hid, and grim and physically interact with them through their baculovirus iap repeat (bir) region. here we examined the functional importance of bir and ring finger motifs of orgyia pseu ...19989852042
expression and cellular distribution of baculovirus-expressed bovine herpesvirus 1 (bhv-1) glycoprotein d (gd) sequences.glycoprotein d (gd) of bovine herpesvirus 1 (bhv-1), a homolog of herpes simplex virus gd, represents a major component of the viral envelope and is a dominant immunogen. to study the antigenic properties of the different regions of gd, we have expressed the full-length gd encoding gene and overlapping fragments spanning various regions of the gd open reading frame in a baculovirus (autographa californica nuclear polyhedrosis virus)--insect cell (spodoptera frugiperda, sf-9) system. maximum leve ...19989856100
coinfection of spodoptera exigua and spodoptera frugiperda cell lines with the nuclear polyhedrosis viruses of autographa californica and spodoptera exigua.the autographa californica multinucleocapsid nuclear polyhedrosis virus (acmnpv) has a broad host range among lepidoptera. in contrast, the spodoptera exigua mnpv (semnpv) can replicate efficiently only in s. exigua larvae or s. exigua-derived cell lines. in this study, we examined the coinfection of s. exigua se301 and spodoptera frugiperda iplb-sf21aeii (sf21) cell lines with semnpv and acmnpv recombinant (ac360-501beta-gal) which was constructed for expression of beta-galactosidase under cont ...199810325534
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 ...19989420274
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 ...19989525621
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 ...19989531493
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 ...19989533078
characterization of a nuclear polyhedrosis virus of spodoptera frugiperda from argentina. 19989538035
new isolate of macosoma neustria nuclear polyhedrosis virus in latvia. 19989538036
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 ...19989542640
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 ...19989557881
baculovirus-mediated gene transfer into mammalian cells.a kind of cytotoxinic gene barnase was cloned downstream of immediate early promoter from cytomegalovirus (cmv). recombinant virus vaccmvbar was constructed using bac-to-bac system by insertion of the expression cassette into the polyhedrin gene locus of autographa californica nuclear polyhedrosis virus (acnpv). cytotoxinic effect caused by expression of barnase was observed in four mammalian cells after vaccmvbar infection dose-dependent analysis revealed that one of the cells hicam was the mos ...199818726228
generation of recombinant baculovirus dna in e.coli using a baculovirus shuttle vector.baculovirus vectors are now widely used to direct the expression of heterologous genes in cultured insect cells and insect larvae. in most cases, heterologous genes placed under transcriptional control of the polyhedrm promoter of the autographa californica nuclear polyhedrosis virus (acnpv) are abundantly expressed during the late stages of infection. the recombinant proteins are usually soluble and functionally similar to their authentic counterparts (l-7). in the following sections, recent ad ...199821390847
nucleotide sequence and characterization of the p10 gene of spodoptera litura nuclear polyhedrosis virus.the p10 gene was localized within the 3.0 kbp bamh i fragment of the sinpv genome. with a coding sequence of 318 nucleotides, corresponding to a protein of 105 amino acids, the p10 gene of sinpv is the longest p10 gene identified so far in npvs. the sinpv p10 gene is also distinct in having two a/tttgta motifs in the promoter region. with 10 heptad repeats, the sinpv p10 protein is probably forming a relatively large coiled-coil structure. the organization of sinpv orf552-p10 gene-orf945 cluster ...199812167986
expression of human lactoferrin cdna in insect cells.a transfer plasmid p8hlfc harboring human lactoferrin cdna was constructed and co-transfected with autographa californica nuclear polyhedrosis virus ( acnpv bacpak6 ) dna into spodoptera frugiperda (sf) cells. the recombinant virus acnpv-hlfc was identified and purified three times by dot hybridization and plaques screening. the expression of human lactoferrin cdna in insect cells was detected by western blotting. the expression level of lactoferrin is about 2% of insect cellular total soluble p ...199812167991
cloning of etp28 gene of eimeria tenella (guangdong strain) sporozoites and its expression in baculovirus expression system.a refractile body antigen etp28 gene of eimeria tenella (guangdong strain) sporozoites was cloned by pcr from the synthesized first strand cdna. it has a high homology with the previously reported etp28 gene of merck strain ls18. the gene was expressed through standard procedures in the modified autographa californica nuclear polyhedrosis virus (acmnpv-occ(-)) expression system and large amount of heterologous fusion protein (gst-6xhis-etp28) was obtained. the expression product was about 21.3% ...199812174264
nucleotide sequence analysis of the hcnpv cysteine protease gene.the cysteine protease (cp) gene of hyphantria cunea nuclear polyhedrosis virus (hcnpv) has been located at the hind iii--3.5 kb fragment. the nucleotide sequence has been determined. the results indicated that its open reading frame of 975 nt encoded the protein of 324 amino acids. the baculovirus late gene promoter taag motif was identified at -24 nt upstream from the start codon atg; the typical poly (a) signal sequence aataaa was detected at 33 nt downstream from the stop codon taa. the hcnpv ...199812174267
[biosynthesis of a single peptide chain containing human chorionic gonadotropin beta and ovine common alpha subunits tandem].hcg beta-olh alpha chimeric cdna was constructed by using overlapping pcr to contact the codons of c-terminal end of hcg beta with the codons of n-terminal end of olh alpha, then it was subcloned into nuclear polyhedrosis virus (acnpv) expression vector pvl1393 to construct expression vector pvl1393-hcg beta-olh alpha. the insect cells (sf9) were cotransfected by the expression vector pvl1393-hcg beta-olh alpha and baculogold acnpv linearized genomic dna, and recombinant viruses acnpv-hcg beta-o ...199812014113
nucleotide sequence analysis of hasnpv protein kinase.the protein kinase gene of helicoverpa armigera single nucleocapsid nuclear polyhedrosis virus (hasnpv) has been cloned and sequenced. it is located approximately 1.25 kb downstream of the polyhedrin gene. the predicted molecular mass of this 267 amino acid protein (havpk) is 31 kd. havpk shows a 43.0% amino acid homology to vpk from lymantria dispar multinucleocapsid nuclear polyhedrosis virus (ldmnpv) and a 39.0% homology to pk-1 from autographa californica multinucleocapsid nuclear polyhedros ...199712219213
studies on the expression of the 28 kd glutathione s-transferase gene from schistosoma japonicum in the silkworm (bombyx mori) larvae and insect cells.the gene of the 28 kd glutathione s-transferase (gst) from the chinese strain of schistosoma japonicum had been expressed in the silkworm (bombyx mori) cells and larvae by bombyx mori nuclear polyhedrosis virus (bmnpv) vector which had been modified. the gst gene was inserted into the right position of the bmnpv genome as identified by southern hybridization. the product was a 28 kd protein, had gst activity and antigenicity. the yield in bmn cells (1x10(6) cells/ml) was 0.77 mg and more than 5 ...199712219234
bcl-2 expression in spodoptera frugiperda sf-9 and trichoplusia ni bti-tn-5b1-4 insect cells: effect on recombinant protein expression and cell viability.the effect of bcl-2 expression on cell viability and recombinant protein synthesis was investigated in the spodoptera frugiperda sf-9 and trichoplusia ni bti-tn-5b1-4 (high fivetrade mark) insect cell lines. it was found that coinfection with a baculovirus expressing bcl-2 [autographa californica nuclear polyhedrosis virus (acnpv)-bcl2] extended the life span of high fivetrade mark cells but not sf-9 cells when compared to infection with recombinant baculoviruses expressing either human tissue p ...199718642241
expression of cell surface gpi-anchored human p97 in baculovirus-infected insect cells.the baculovirus/insect cell system (autographa californica multiple nuclear polyhedrosis virus/spodoptera frugiperda sf9 cells) was used to express the gpi-anchored human melanoma tumor antigen, melanotransferrin or p97. this system served to study the expression and productivity of recombinant gpi-anchored p97 by insect cells. the sf9 cells expressed a cell surface gpi-anchored form of p97 as well as a soluble form of p97 that did not appear to be derived from the gpi-anchored form of p97. both ...199718636443
substrate limitation in the baculovirus expression vector system.the inability to infect insect cell cultures at the highest achievable cell densities has imposed major limitations to both the fundamental understanding of the baculovirus expression vector system (bevs) as well as full exploitation of its potential productive capacity for recombinant (beta-galacnpv) products. the current literature does not characterize and identify the exact nature of the observed limitations, which therefore has become the major objective and contribution of the following st ...199718636607
expression of green fluorescent protein in insect larvae and its application for heterologous protein production.many eukaryotic proteins have been successfully expressed in insect cells infected with a recombinant baculovirus derived from the autographa californica nuclear polyhedrosis virus (acnpv). there are, however, disadvantages with this cell-based system when carried out in suspension cultures at high bioreactor volume (e.g., limited oxygen transfer, susceptibility to contamination, high cost). these problems can be avoided by using whole larvae as the "reactors." there are, however, other problems ...199718636639
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 ( ...19979563680
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 ...19979426459
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 ...19978995679
replication of simian virus 40 origin-containing dna during infection with a recombinant autographa californica multiple nuclear polyhedrosis virus expressing large t antigen.autographica californica multiple nuclear polyhedrosis virus (acmnpv) has been shown to encode many of the enzymes involved in the replication of its own dna. although the acmnpv genome contains multiple sets of reiterated sequences that are thought to function as origins of dna replication, no initiator protein has yet been identified in the set of viral replication enzymes. in this study, the ability of a heterologous origin initiator system to promote dna replication in acmnpv-infected cells ...19978985377
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 ...19979217053
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 ( ...19979237352
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 ...19979243790
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 ...19979268770
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 ...19979281399
ingestion time does not influence the susceptibility of trichoplusia ni to a nuclear polyhedrosis virus 19979281407
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 ...19979281505
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 ...19979282319
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 ...19979300047
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 ...19979311561
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 ...19979311824
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 ...19979311840
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 ...19979311875
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 ...19979311884
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 ...19979325155
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 ...19979343163
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 ...19979352215
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 ...19979366090
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 ...19979371585
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 ...19979371622
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 ...19979374595
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 ...19979381798
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 ...19979388209
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 ...19979400955
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 ...19979406188
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 ...19979007067
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