Identification of genes involved in DNA replication of the Autographa californica baculovirus.
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ABSTRACT:
SUBMITTER: Kool M
PROVIDER: S-EPMC45197 | biostudies-other | 1994 Nov
REPOSITORIES: biostudies-other
Publications
Identification of genes involved in DNA replication of the Autographa californica baculovirus.
Kool M M Ahrens C H CH Goldbach R W RW Rohrmann G F GF Vlak J M JM
Proceedings of the National Academy of Sciences of the United States of America 19941101 23
By use of a transient replication assay, nine genes involved in DNA replication were identified in the genome of the Autographa californica baculovirus. Six genes encoding helicase, DNA polymerase, IE-1, LEF-1, LEF-2, and LEF-3 are essential for DNA replication while three genes encoding P35, IE-2, and PE38 stimulate DNA replication. No stimulation by the AcMNPV pcna gene, encoding a protein with sequence homology to proliferating-cell nuclear antigen, was observed. A pattern of amino acids foun ...[more]
Similar Datasets
Project description:A gene that promotes Autographa californica M nuclear polyhedrosis virus (AcMNPV) replication in IPLB-Ld652Y cells, a cell line that is nonpermissive for AcMNPV, was identified in Lymantria dispar M nuclear polyhedrosis virus (LdMNPV). Cotransfection of AcMNPV DNA and a plasmid carrying the LdMNPV gene into IPLB-Ld652Y cells results in AcMNPV replication. The gene maps between 43.3 and 43.8 map units on the 162-kbp genome of LdMNPV. It comprises a 218-codon open reading frame and encodes a polypeptide with a predicted molecular mass of 25.7 kDa. The predicted polypeptide is glutamic acid and valine rich and negatively charged, with a pI of 4.61. No protein sequence motifs were identified, and no matches with known nucleotide or peptide sequences were found in the AcMNPV genome or database searches that suggest how this gene might function. A recombinant AcMNPV bearing the LdMNPV gene overcomes a block in protein synthesis observed in AcMNPV-infected IPLB-Ld652Y cells. Using Southern blotting techniques, we were unable to identify a homolog in Orgyia pseudotsugata M nuclear polyhedrosis virus, a baculovirus that is routinely propagated in IPLB-Ld652Y cells. This suggests that the LdMNPV host range is unique among the baculoviruses studied to date. We named this gene hrf-1 (for host range factor 1).
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Project description:Baculoviruses are large double-stranded DNA viruses that are virulent pathogens of certain insect species. In a natural host, Trichoplusia ni, infection by the model baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) begins when the occluded form of the virus disassembles in the midgut and virions infect midgut epithelial cells to establish the primary phase of the infection. To better understand the primary phase of the AcMNPV infection cycle, newly molted 5th-instar T. ni larvae were orally infected with AcMNPV occlusion bodies and the transcriptional responses of the T. ni midgut were analyzed at various times from 0 to 72 h postinfection, using transcriptome sequencing analysis and a T. ni reference genome. The numbers of differentially expressed host genes increased as the infection progressed, and we identified a total of 3,372 differentially expressed T. ni transcripts in the AcMNPV-infected midgut. Genes encoding orthologs of HMG176, atlastin, and CPH43 were among the most dramatically upregulated in response to AcMNPV infection. A number of cytochrome P450 genes were downregulated in response to infection. We also identified the effects of AcMNPV infection on a large variety of genes associated with innate immunity. This analysis provides an abundance of new and detailed information on host responses to baculovirus infection during the primary phase of the infection in the midgut and will be important for understanding how baculoviruses establish productive infections in the organism.IMPORTANCE Baculoviruses are virulent pathogens of a number of important insect pest species. In the host Trichoplusia ni, infection begins in the midgut when infectious virions of the occlusion-derived virus (ODV) phenotype enter and subsequently replicate in cells of the midgut epithelium. A second virion phenotype (budded virus [BV]) is produced there, and BV mediates systemic infection of the animal. Most prior detailed studies of baculovirus infections have focused on BV infections of cultured cells. In this study, we examined the transcriptional responses of the T. ni midgut to infection by ODV of the baculovirus AcMNPV and identified a variety of host genes that respond dramatically to viral infection. Understanding the transcriptional responses of the host midgut to viral infection is critically important for understanding the biphasic infection in the animal as a whole.
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