Herpesvirus papio encodes a functional homologue of the Epstein–Barr virus apoptosis suppressor, BHRF1

The human tumour virus Epstein–Barr virus (EBV) encodes a 17 kDa protein, BHRF1, which is a member of the Bcl-2 family and has been shown to suppress apoptosis. The role of this gene in the life-cycle of EBV has not been fully elucidated. In order to identify motifs conserved in herpesviruses and possibly shed light on its function we isolated a BHRF1 homologue from herpesvirus papio (cerco-pithecine herpesvirus-12) a closely related gamma-herpesvirus of baboons. The gene, hvpBHRF1, also encodes a 17 kDa protein which shares 64% identity and 79 % similarity with EBV BHRF1 at the amino acid level. In biological assays, hvpBHRF1 and BHRF1 conferred similar levels of protection on human keratinocytes induced to apoptose with cis-platin. Greater than 90 % of the human population are infected for life with Epstein–Barr virus (EBV) and a similar percentage of captive baboons are seropositive for herpesvirus papio (HVP) (Jenson et al., 2000). DNA sequence analysis and studies on genome organization and gene function indicate that EBV is more closely related to HVP than any other human herpesvirus (Heller &Kieff, 1981; Heller et al., 1981; Ryon et al., 1993;Yates et al., 1996). Both belong to the lymphocryptovirus subfamily of gammaherpesviruses. Many of the EBV genes associated with latency and biological features such as the ability to infect and growth transform B cells are conserved (Falk et al., 1977; Moghaddam et al., 1998). EBV genes like the EBERs (Toczysk