Sequencing of bovine herpesvirus 4 v.test strain reveals important genome features

Abstract

BackgroundBovine herpesvirus 4 (BoHV-4) is a useful model for the human pathogenic gammaherpesviruses Epstein-Barr virus and Kaposi's Sarcoma-associated Herpesvirus. Although genome manipulations of this virus have been greatly facilitated by the cloning of the BoHV-4 V.test strain as a Bacterial Artificial Chromosome (BAC), the lack of a complete genome sequence for this strain limits its experimental use.MethodsIn this study, we have determined the complete sequence of BoHV-4 V.test strain by a pyrosequencing approach.ResultsThe long unique coding region (LUR) consists of 108,241 bp encoding at least 79 open reading frames and is flanked by several polyrepetitive DNA units (prDNA). As previously suggested, we showed that the prDNA unit located at the left prDNA-LUR junction (prDNA-G) differs from the other prDNA units (prDNA-inner). Namely, the prDNA-G unit lacks the conserved pac-2 cleavage and packaging signal in its right terminal region. Based on the mechanisms of cleavage and packaging of herpesvirus genomes, this feature implies that only genomes bearing left and right end prDNA units are encapsulated into virions.ConclusionsIn this study, we have determined the complete genome sequence of the BAC-cloned BoHV-4 V.test strain and identified genome organization features that could be important in other herpesviruses.

Proteomic Characterization of Bovine Herpesvirus 4 Extracellular Virions

“…Based on comparisons with other Gammaherpesvirinae, BoHV-4 tegument is predicted to contain ϳ15 proteins. Proteomic analysis of BoHV-4 virions identified 13 of these proteins (the products of ORFs 3,33,35,38,42,45,48,52,55,63,64,67, and 75 [ Tables 1 and 2]). In contrast, the BoHV-4 thymidine kinase (TK), encoded by ORF21, was not detected in virions (Table 1).…”

“…The BoHV-4 genome is estimated to encode at least 79 open reading frames (ORFs) (42,59). Like all herpesviruses, BoHV-4 virions are composed of a large (diameter Ͼ 100 nm) icosahedral nucleocapsid, which is assembled in the nucleus from at least eight different conserved proteins (1).…”

“…The mass lists obtained in the different complete virions analyses were searched against this database using the criteria stated above. Detected peptides were graphically mapped onto the BoHV-4 v.test genome which also displayed the predicted ORFs as defined previously (42). The results were generated and visualized using R (49) and the SeqinR package (9).…”

“…The default search parameters used were as follows: enzyme ϭ trypsin; maximum missed cleavages ϭ 2; fixed modifications ϭ carbamidomethyl (C); variable modifications ϭ oxidation (M); peptide tolerance Ϯ 1.5 Da (Da); MS/MS tolerance Ϯ 0.5 Da; peptide charge ϭ 2ϩ and 3ϩ; and instrument ϭ ESI-TRAP. All data were also searched against the NCBI Bos taurus database in order to detect host proteins host proteins or against a BoHV-4 v.test database (42) to detect viral proteins. Only sequences identified with a Mascot score greater than 30 were considered, and single peptide identification was systematically evaluated manually.…”

Tissular Distribution of Argentinean Strains of Bovine Herpesvirus Type 4 (BoHV-4) in Experimentally-Infected Calves

“…It has also been reported that there are genomic variations among BoHV-4 isolates from different regions. Emerging strains, whose restriction patterns do not fully match to the and European (V test, and Movar LVR140) reference strains groups have also been described , Palmeira et al 2011). This variability is attributed to recombination events among strains and within the same strain, mainly in polyrepetitive DNA (prDNA) sequences located on both sides of the long unique region (LUR) of the genome, during viral replication (Bublot et al 1991b, Donofrio et al 2000a, Nikolin et al 2007).…”