Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2003
Publication Date: 10/20/2003
Citation: Delhon, G., Moraes, M.P., Lu, Z., Afonso, C.L., Flores, E.F., Weiblen, R., Kutish, G.F., Rock, D.L. 2003. Genome of bovine herpesvirus 5. Journal of Virology. 77(19):10339-10347. Interpretive Summary: The genome sequence of Bovine herpesvirus type 5 (BHV-5), an alphaherpesvirus responsible for fatal encephalitis in cattle, is described and compared to that of the closely related BHV-1 which causes respiratory disease. BHV-5 and BHV-1 proteins average 82% amino acid identity with the highest similarity in DNA replication and processing proteins. Among the most divergent proteins are those encoding for immediate-early (IE) proteins, regulators of the expression of all classes of viral genes. Marked differences are also found in the latency-related (LR) region which has been implicated in the regulation of BHV-1 latency. Differences in IE proteins and the LR region may be significant for virus-neuron interactions and likely contribute to BHV-5 neuropathogenicity. Availability of BHV-5 and BHV-1 genome sequences will permit to investigate the molecular basis of neuropathogenicity by constructing chimeric viruses.
Technical Abstract: Here we present the complete genomic sequence of bovine herpesvirus 5 (BHV-5), an alphaherpesvirus responsible for fatal meningoencephalitis in cattle. The 138,390-bp genome encodes 70 putative proteins and resembles the a2 subgroup of herpesviruses in genomic organization and gene content. BHV-5 is very similar to BHV-1, the etiological agent of infectious bovine rhinotracheitis, as reflected by the high level of amino acid identity in their protein repertoires (average, 82%). The highest similarity to BHV-1 products (> 95% amino acid identity) is found in proteins involved in viral DNA replication and processing (UL5, UL15, UL29, and U139) and in virion proteins (UL14, UL19, UL48, and US6). Among the least conserved (< 75%) are the homologues of immediate-early (IE) proteins BICPO, BICP4, and BICP22, the three proteins being longer in BHV-5 than in BHV-1. The structure of the BHV-5 latency-related (LR) region departs markedly from that of BHV-1 in both coding and transcriptional regulatory regions. Given the potential significance of IE genes and the LR region in virus-neuron interactions, it is likely these differences contribute to BHV-5 neuropathogenicity.