title: Amino acid tandem repeats within a late viral gene define the central variable region of African swine fever virus.
abstract: The central variable region (CVR) of the African swine fever virus (ASFV) genome is contained within the 9-RL open reading frame (ORF). ORF 9-RL of the ASFV isolate Malawi Lil-20/1 predicts a protein of 614 amino acids with amino- and carboxy-terminal hydrophobic regions and a centrally located hydrophilic region. The CVR of the genome, located centrally within this ORF, is 372 bp and contains a 132-bp direct repeat. The translated CVR within ORF 9-RL contains 31 tandem tetramers, predominantly NADT, NANT, NVDT, and, in a few cases, CAST, GAST, or CADT. In vitro translation of 9-RL yielded a 94-kDa protein that was strongly reactive with convalescent pig serum while monospecific 9-RL antiserum identified a late viral protein of 94 kDa in ASFV-infected macrophages. The protein, detected by immunofluorescence staining with 9-RL antiserum, was distributed homogeneously throughout the cytoplasm of infected Vero cells. 9-RL protein size varied among different viral isolates and among cell-culture-adapted viruses. Protein size increased proportionately with the degree of cell culture adaptation and was directly correlated with the size of the CVR present within the ORF (300-500 bp). Analysis of the number and composition of tandem tetramers present within the CVR of a given ASFV isolate may prove useful for identifying and/or grouping ASFV isolates.
authors.affiliation: Plum Island Animal Disease Center, ARS, USDA, Greenport, New York 11944-0848, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Irusta
authors.forename: M V
authors.initials: MV
authors.lastname: Borca
authors.forename: G F
authors.initials: GF
authors.lastname: Kutish
authors.forename: Z
authors.initials: Z
authors.lastname: Lu
authors.forename: E
authors.initials: E
authors.lastname: Caler
authors.forename: C
authors.initials: C
authors.lastname: Carrillo
authors.forename: D L
authors.initials: DL
authors.lastname: Rock
mesh_terms: D000358:African Swine Fever Virus / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D003062:Codon; D017931:DNA Primers; D015870:Gene Expression; D005814:Genes, Viral; D014644:Genetic Variation; D008264:Macrophages / Q000166:cytology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012091:Repetitive Sequences, Nucleic Acid; D013552:Swine; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: C099866:9-RL protein, African swine fever virus; D003062:Codon; D017931:DNA Primers; D014764:Viral Proteins