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Biomedical subjects

D H Bishop

Publications and source records attributed to D H Bishop.

At least 73 records · Page 4Linked to original sources
PubMed1987

Secretion of particles of hepatitis B surface antigen from insect cells using a baculovirus vector.

The coding sequences of the hepatitis B virus surface antigen were inserted into a baculovirus transfer vector produced from Autographa californica nuclear polyhedrosis virus (AcNPV) so that the foreign gene was under the control of the AcNPV polyhedrin promoter. Spodoptera frugiperda cells infected with the derived recombinant baculovirus produced and secreted 22 nm particles containing the hepatitis B surface antigen. The particles had morphological and antigenic properties identical to those of 22 nm particles isolated from the plasma of chronic active hepatitis patients.

Animals↗
PubMed1987

Baculovirus expression vectors: the requirements for high level expression of proteins, including glycoproteins.

The requirements for high level expression of three foreign proteins using the polyhedrin gene promoter of Autographa californica nuclear polyhedrosis virus (AcNPV, Baculoviridae) have been investigated. In Spodoptera frugiperda cells infected with the appropriate recombinant baculoviruses, the synthesis of the two S RNA coded genes of lymphocytic choriomeningitis virus (LCMV; i.e. the nucleoprotein, N, and glycoprotein precursor, GPC), or the haemagglutinin gene of influenza A virus, appears to be related to the degree of integrity of the 5' upstream sequence of the polyhedrin gene. No effect on the level of N protein expression was detected when all the polyhedrin gene coding sequences or some of the immediate 3' downstream sequences were deleted. Using the most efficient expression viruses derived from a new transfer vector, pAcYM1, it has been estimated that LCMV N protein represented approximately 50% of the total cellular protein, an observation consistent with the presence of numerous inclusion bodies in the cytoplasm of infected cells. For recombinant viruses derived from the pAcYM1 transfer vector containing the LCMV GPC gene, the level of synthesis of the arenavirus glycoprotein was equivalent to approximately 20% of the cellular protein. Thin sections of cells infected with the GPC recombinant revealed a highly vacuolated cytoplasm.

Base Sequence↗
PubMed1986

Expression of the S-coded genes of lymphocytic choriomeningitis arenavirus using a baculovirus vector.

A DNA copy of the lymphocytic choriomeningitis virus (LCMV, WE strain)S RNA species has been inserted in both orientations into plasmids containing a 7.1 kb DNA sequence of the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). The inserts were placed behind the polyhedrin gene promoter of AcNPV and in the place of the nucleotide sequences including and flanking the polyhedrin gene translation initiation codon. The derived plasmids were used to obtain recombinant AcNPV viruses after transfection of Spodoptera frugiperda cells in the presence of infectious AcNPV DNA and the selection of polyhedrin-negative viruses. The expression of the two LCMV S-coded genes, the nucleoprotein and glycoprotein precursor, in S. frugiperda cells by the recombinant baculoviruses is described. Based on the results obtained with three different expression vectors, the site of insertion of the foreign genes in the 5' non-coding region of the polyhedrin gene appears to be an important determinant of the level of expression obtained.

Animals↗
PubMed1986

Ambisense RNA viruses: positive and negative polarities combined in RNA virus genomes.

The coding strategies of arenaviruses (family Arenaviridae) and members of the Phlebovirus genus of the Bunyaviridae differ from those of other negative-sense RNA viruses in that some proteins are coded in viral-complementary RNA sequences and others are coded in the viral RNA sequence. The term ambisense RNA has been proposed to denote these unique coding arrangements. The implications of the ambisense RNA coding strategy for the evolution and infection processes of these viruses are discussed.

Arenaviridae↗
PubMed1985

Evolution of bunyaviruses by genome reassortment in dually infected mosquitoes (Aedes triseriatus).

Aedes triseriatus mosquitoes became dually infected after ingesting two mutants of LaCrosse (LAC) virus simultaneously or after ingesting, by interrupted feeding, the two viruses sequentially within a 2-day period. After 2 weeks of incubation, approximately 25 percent of the vectors contained new virus genotypes as the result of RNA segment reassortment. New viruses were transmitted when the mosquitoes fed on mice. Viruses ingested more than 2 days after the initial infecting virus did not cause superinfection of the mosquito vectors.

Aedes↗
PubMed1985

Complete sequences of the glycoproteins and M RNA of Punta Toro phlebovirus compared to those of Rift Valley fever virus.

The complete sequence of Punta Toro virus (Phlebovirus, Bunyaviridae) middle size (M), RNA has been determined. The RNA is 4330 nucleotides long (mol wt 1.46 X 10(6), base composition: 26.7% A, 33.6% U, 18.5% G, 21.2% C) and has 3'- and 5'-terminal sequences that, depending on the arrangement, are complementary for some 15 residues. The viral RNA codes in its viral-complementary sequence for a single primary gene product (the viral glycoprotein precursor) that is comprised of 1313 amino acids (146,376 Da) and is abundant in cysteine residues but has few potential asparagine-linked glycosylation sites. The 5'-noncoding region of the Punta Toro M viral-complementary RNA is short (16 nucleotides); the 3'-noncoding sequence is much longer (372 nucleotides). The latter is rich in short stretches of adenylate residues, like the 3'-noncoding regions of the Punta Toro S mRNA species (T. Ihara, H. Akashi, and D. H. L. Bishop, 1984, Virology 136, 293-306). No other large open reading frame has been identified in either the viral, or viral-complementary, M RNA sequences. Limited amino-terminal sequence analyses of the two viral glycoproteins have indicated the gene order and potential cleavage sites in the glycoprotein precursor. The data suggest the existence of a 30 X 10(3)-Da polypeptide (designated NSM) in the glycoprotein precursor that precedes the G1 protein (i.e., gene product order: NSM-G1-G2). Examination of the sequence of the Punta Toro M gene product reveals the presence of multiple hydrophobic sequences including a 19-amino acid, carboxy-proximal, hydrophobic region (G2). This hydrophobic sequence is followed by a 13-amino acid-terminal sequence rich in charged amino acids. The size and constitution of the carboxy-terminal region is consistent with a transmembranal and anchor function for the glycoprotein in the viral envelope. Other regions of the glycoprotein precursor contain sequences of amino acids with a predominantly hydrophobic character (23, 50, and 20 amino acids in length). Their functions are unknown. The amino terminus of the G1 protein is located near the end of the 23-amino acid-long hydrophobic sequence of the presumptive precursor, the hydrophobic 50-amino acid sequence lies within G1, and the amino terminus of G2 is located in the middle of the 20-amino acid-long hydrophobic sequence.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1985

Analyses of the mRNA transcription processes of Punta Toro phlebovirus (Bunyaviridae).

The time course of the syntheses of Punta Toro (PT) phlebovirus (Bunyaviridae) small (S)-size viral RNA (S vRNA), viral complementary RNA (S vcRNA), and messenger RNA (S mRNA) species has been analyzed using single-stranded DNA probes representing the two S-coded gene products. The data obtained support the conclusion that PT S RNA has an ambisense coding strategy (T. Ihara, H. Akashi, and D. H. L. Bishop, Virology 136, 293-306, 1984) with the viral nucleocapsid protein, N, encoded in a viral-complementary, subgenomic, mRNA species and a putative nonstructural protein, NSs, encoded in a viral-sense, subgenomic, second S mRNA species. In the absence of puromycin (or cycloheximide) full-length S vRNA, S vcRNA, and subgenomic N mRNA and putative NSs mRNA species were identified in PT virus-infected cell extracts. In the presence of inhibitors of protein synthesis (puromycin or cycloheximide) newly synthesized N mRNA species were detected, but not full-length S vcRNA, nor S vRNA, nor the S coded NSs mRNA species. The mRNA species recovered from drug-treated cells have been translated in vitro to synthesize viral N protein. Analyses of the 5' ends of the N and NSs mRNA species have shown them to be heterogeneous in sequence and some 11-18 bases longer than the ends of the genomic RNA species, indicating that they represent nonviral primer sequences like those identified for bunyavirus mRNA species (D. H. L. Bishop, M. E. Gay, and Y. Matsuoka, Nucleic Acids Res. 11, 6409-6418, 1983). The presence of such additional sequences on mRNA derived from representatives of two Bunyaviridae genera appears by these analyses to be a more conserved feature than the S RNA coding arrangement of the respective viruses.

Animals↗
PubMed1985

Complete sequence of the S RNA of lymphocytic choriomeningitis virus (WE strain) compared to that of Pichinde arenavirus.

Previous studies have reported that the 3' half of the small, S, RNA species of the WE strain of lymphocytic choriomeningitis (LCM) virus codes for the viral nucleoprotein in a subgenomic, viral-complementary, mRNA species (Romanowski, V. and Bishop, D.H.L. (1985) Virus Res. 2, 35-51). The complete sequence of the LCM-WE S RNA has now been obtained, indicating that the 5' half of the RNA codes for the viral glycoprotein precursor in a viral-sense sequence that does not overlap the N gene. It is concluded that, like Pichinde virus (Auperin, D. et al. (1984) J. Virol. 52, 897-904), LCM has an ambisense S RNA coding strategy. The LCM-WE S RNA is 3375 nucleotides in length, has a size of 1.14 X 10(6) Da and base composition of 26.1% A, 23.2% C, 21.5% G, 29.2% U. The 3' and 5' end sequences of the S RNA are complementary for some 30 nucleotides, depending on the arrangement. The non-coding regions at the two ends are 77 (5') and 60 (3') nucleotides long. The glycoprotein precursor has a primary amino acid size of 56293 Da and is rich in potential glycosylation sites as well as histidine and cysteine residues. It has both amino and carboxy proximal hydrophobic regions. The LCM-WE S RNA and predicted protein sequence data have been compared to those of Pichinde arena-virus. Extensive RNA and protein sequence homology exists for the two S RNA species, although the homology for the glycoprotein sequences of the two viruses (39%) is less than the 50% observed for the two viral nucleoproteins.

Amino Acid Sequence↗
PubMed1985

Conserved sequences and coding of two strains of lymphocytic choriomeningitis virus (WE and ARM) and Pichinde arenavirus.

Analyses of the 3' end sequences of the small, S, and large, L, RNA species of lymphocytic choriomeningitis (LCM) virus isolates ARM and WE, and DNA clones of LCM-WE, have shown that there are extensive RNA sequence homologies between the 3' ends of the two RNA species of both LCM strains. Limited sequence data of DNA clones representing the LCM-WE L RNA species indicate that a gene product (presumably the minor 200 kdalton virion protein) is coded in a viral-complementary mRNA species. Sequence analyses of LCM-WE S DNA clones indicate that approximately 50% of the 2040 nucleotides representing the 3' half of the viral RNA species (and its encoded 558 amino acid gene product) are identical in type and position to those of Pichinde arenavirus (Auperin, D., et al. (1984a), Virology 134, 208-219). For Pichinde virus, it has been shown that the 3' proximal gene product (the nucleoprotein, N) is translated from a subgenomic, viral-complementary mRNA (Auperin et al., 1984a). Data have recently been obtained (Auperin, D., et al. (1984b) J. Virol., in press) that indicate that the Pichinde glycoprotein precursor, GPC, is coded in a viral-sense subgenomic mRNA species corresponding to the 5' half of the S RNA. The nucleotide sequence that immediately follows the N coding region of both LCM-WE and Pichinde viruses can be arranged in a hairpin configuration. In view of this, and if, like Pichinde virus, LCM has an ambisense S RNA coding strategy, then it is probable that the intergenic hairpins function as transcription terminators for the N and GPC mRNA species of both viruses.

Amino Acid Sequence↗
PubMed1985

Analyses of the mRNA transcription processes of snowshoe hare bunyavirus S and M RNA species.

The time course of synthesis of snowshoe hare bunyavirus small (S)- and medium (M)-sized viral RNA (vRNA), viral cRNA (vcRNA), and mRNA species was analyzed by using single-stranded DNA probes representing the S- and M-coded gene products. In the presence of puromycin, an inhibitor of protein synthesis, the subgenomic S mRNA species were detected, but not full-length S vcRNA or S vRNA species. No M-related RNA species were identified in puromycin-treated cells. In the absence of puromycin, full-length M and S vRNA, S vcRNA, and subgenomic S mRNA species were observed, as well as apparently full-length M vcRNA species, presumably including the approximately similar-sized M mRNA species. The 5' ends of the S and M mRNA species have been shown to be heterogeneous and some 12 to 17 bases longer than the ends of their corresponding presumptive replicative vcRNA species, in agreement with an earlier report that they represent nonviral primer sequences (D. H. L. Bishop, M. E. Gay, and Y. Matsuoko, Nucleic Acids Res. 11:6409-6418, 1983). The 3' ends of the M and S mRNA species were found to be shorter by some 60 and 100 nucleotides, respectively, than those of their corresponding full-length vcRNA species. Comparison of the 3' noncoding regions of the S and M vcRNA species revealed that there are conserved sequences following the translation termination codons of the two RNA species. One of these conserved sequences is a pyrimidine-rich template sequence that is approximately 20 nucleotides beyond the deduced S mRNA transcription termination site.

Base Sequence↗
PubMed1985

The genetic basis for describing viruses as species.

The basis for the taxonomic definition of viruses or other species eventually has to be genetic. Since the beginning of the taxonomical considerations of organisms, the criterion that individuals can be grouped together on the basis of genetic compatibilities has been adopted as the guiding principle for describing a species. Although the genetic tests for grouping and distinguishing viruses may be different, the principle behind the species concept can still be applied. Also, the very existence of virus heredity and invokes the concept of speciation.

Bunyaviridae↗
PubMed1984

Novel coding strategy (ambisense genomic RNA) revealed by sequence analyses of Punta Toro Phlebovirus S RNA.

Sequence analyses of Punta Toro viral S RNA species indicate the existence of a novel coding strategy for RNA viruses that involves both viral complementary and viral sense mRNA species. The Punta Toro nucleocapsid protein (N, 26.9 X 10(3) Da) is coded by a discrete viral complementary mRNA species corresponding to the 3' half of the viral S RNA. A second, presumably nonstructural, gene product (NS, 29.1 X 10(3) Da) is coded by a viral sense mRNA species that corresponds to the 5' half of the viral RNA. The ambisense nature of the S RNA is unique by comparison with any other viral RNA and raises questions concerning the family assignment of phleboviruses.

Amino Acid Sequence↗
PubMed1984

The sequences of the N protein gene and intergenic region of the S RNA of pichinde arenavirus.

Two overlapping DNA clones representing more than half of the Pichinde arenavirus S RNA segment were cloned into pBR322 and their nucleotide sequences were determined. The analyses predict that the viral nucleocapsid protein (N) is encoded in a reading frame in the viral complementary RNA sequence starting at viral S RNA nucleotide residue 84 from the 3' end and terminating with an opal codon at residues 1767-1769. The position of the termination codon has been confirmed by primer directed dideoxynucleotide sequencing. The N protein has a calculated size of 62,911 Da and a net positive charge of +9. Viral complementary 15 S mRNA that directs the synthesis of N protein and hybridizes to the predicted N gene DNA has been identified in infected cell extracts. A second nonoverlapping reading frame in the viral complementary sequence originates at nucleotide position 1827 and remains open for at least 71 amino acids (i.e., the extent of the second clone). A long stretch of hydrophobic amino acids is near the amino terminus of this predicted gene product. Between the two reading frames is a 60-nucleotide-long noncoding intergenic region. This nucleotide sequence can be arranged in hairpin configuration involving 14 G-C and 4 A-U base pairs. The possible function of this intergenic region in the regulation of transcription and/or translation is discussed.

Amino Acid Sequence↗
PubMed1984

The complete sequence of the M RNA of snowshoe hare bunyavirus reveals the presence of internal hydrophobic domains in the viral glycoprotein.

The complete sequence of the viral M RNA of snowshoe hare (SSH) bunyavirus has been determined. The RNA is 4527 nucleotides long (mol wt: 1.5 X 10(6), base composition: 27.5% A, 33.5% U, 17.7% G, 21.3% C), and has 3' and 5' terminal sequences that, depending on how they are arranged, are complementary for some 44 residues. The viral RNA codes in its viral-complementary sequence, for a single primary gene product (the viral glycoprotein) that is comprised of 1441 amino acids (162,391 Da), and is rich in cysteine residues but poor in potential asparagine-linked glycosylation sites. Like the SSH S RNA, the M viral-complementary 5' noncoding region is shorter than the 3' noncoding sequence (61 as opposed to 142 nucleotides). The different functions of the M RNA are discussed in relation to those of the S RNA of SSH virus. No other large open reading frames have been identified in either the viral, or viral-complementary, M RNA sequences. Examination of the sequence of the M gene product reveals the presence of an 18 residue amino terminal hydrophobic sequence (putative signal) and a much longer 32 amino acid carboxy proximal hydrophobic region that is followed by a terminal sequence rich in charged amino acids (12 out of 20 residues). The size and constitution of the carboxy end regions are consistent with a transmembranal and anchor function for the glycoprotein in the viral envelope. In addition to these terminal hydrophobic sequences, a localized internal region of the gene product contains several hydrophobic sequences, 15 to 29 amino acids in length. Their possible role in the morphogenesis of bunyaviruses that occurs in the Golgi cisternae of infected cells is discussed.

Amino Acid Sequence↗