Cytopathogenicity of border disease virus is correlated with integration of cellular sequences into the viral genome

Abstract

Two border disease virus (BDV) pairs each consisting of cytopathogenic (cp) and non-cp viruses have been analyzed at the molecular level. Within the NS2-3 (p125) encoding region of both cp viruses, insertions of cellular sequences were identified which were absent in the corresponding non-cp isolates. A comparative sequence analysis revealed that within each pair the cp and non-cp viruses are almost identical. This strongly suggests that the cp BDV isolates developed from the non-cp viruses by RNA recombination between the viral genome and cellular sequences. Nonstructural protein NS3 (p80) was demonstrated after infection with both cp BDV strains. In addition, fusion proteins composed of cellular and viral sequences were identified. In contrast, expression of NS3 and the fusion proteins was not found after infection with the respective non-cp counterparts.

Inactivation of the RNase Activity of Glycoprotein E rns of Classical Swine Fever Virus Results in a Cytopathogenic Virus

“…To inactivate the RNase activity of E rns , the histidine residue in the first and/or second RNase domain was replaced by a lysine residue. In a two-step PCR, the CAT codon at position 297 [HϾK(1)] or the CAT codon at position 346 [HϾK (2)] in the amino acid sequence of CSFV strain C (24) was replaced by an AAA codon; alternatively, both codons were replaced [HϾK (1,2)]. In Fig.…”

“…The crude PCR products were BamHI digested, and the 720-bp mutated E rns genes were isolated from an agarose gel and fused to the signal sequence of glycoprotein gG of pseudorabies virus in the baculovirus transfer vector pAcAS3gX as described previously (11). A transfer vector with an E rns gene in which the histidines in both domains were substituted with lysines [HϾK(1,2)] was constructed as described above, except that, in the first PCR, the transfer vector with the mutation in the second domain [HϾK (2)] was used as a template and the HϾK(1) primer was used as a forward primer.…”

“…Pestiviruses are small, enveloped, positive-stranded RNA viruses (23). The genome of pestiviruses varies in length from 12.5 to 16.5 kb (1,2,7,17,19,25,26,28,32) and contains a single large open reading frame (ORF) (1,7,8,17,26). The ORF is translated into a polyprotein which is processed into mature proteins by viral and host cell proteases (30).…”

Bioinformatic mapping of AlkB homology domains in viruses

“…There are two biotopes of the pestiviruses, cytopathogenic (cp) and noncytopatogenic (noncp). The host is infected by the noncp form which is converted into the cp form by integration of a fragment of a cellular gene into the viral genome [36]. This introduces a protease cleavage site in the polyprotein.…”

A long distance RT-PCR able to amplify the Pestivirus genome

“…Herniou et al, 2001;Avalos-Ramirez et al, 2001) to viral molecular biology (e.g. Kümmerer et al, 1998Kümmerer et al, , 2000Becher et al, 1996). Traditional sequencing strategies can be cumbersome and time consuming due to library construction and screening processes, developing of overlapping RT-PCR reactions and problems related to DNA sequence automation.…”