Epstein-Barr virus encodes a novel homolog of the bcl-2 oncogene that inhibits apoptosis and associates with Bax and Bak

The sequenced gammaherpesviruses each contain a single viral bcl-2 homolog (v-bcl-2) which may encode a protein that functions in preventing the apopt otic death of virus-infected cells. Epstein-Barr virus (EBV), a gammaherpes virus associated with several lymphoid and epithelial malignancies, encodes the v-Bcl-2 homolog BHRF1. In this report the previously uncharacterized B ALF1 open reading frame in EBV is identified as having significant sequence similarity to other v-bcl-2 homologs and cellular bcl-2. Transfection of c ells with a BALF1 cDNA conferred apoptosis resistance. Furthermore, a recom binant green fluorescent protein-BALF1 fusion protein suppressed apoptosis and associated with Bar and Bak These results indicate that EBV encodes a s econd functional v-bcl-2.