THE BOVINE HERPESVIRUS TYPE-1 U-L-3.5 OPEN READING FRAME ENCODES A VIRION STRUCTURAL PROTEIN

The bovine herpesvirus type 1 (BHV-1) open reading frame (ORF) U(L)3.5 is similar to ORFs found in pseudorabies virus, infectious laryngotra cheitis virus, equine herpesvirus type 1, and varicella zoster virus, but clearly absent from herpes simplex virus. The published sequence f or this ORF predicts a 126-amino-acid (13.2 kDa) protein product with an isoelectric point of 12.3. We confirmed the U(L)3.5 sequence, expre ssed the ORF as a glutathione-S-transferase fusion protein, and made r abbit antibodies against the purified fusion protein. The antiserum de tected a 13-kDa protein in Western blots of MDBK cells infected with B HV-1, but not with other herpesviruses or uninfected cells. The BHV-1 U(L)3.5 protein was characterized as a component of the virion envelop e or tegument because it was expressed as a late protein, it was prese nt in the cytoplasm but not the nucleus of infected cells, and it was removed from purified virions by detergent extraction. (C) 1998 Academ ic Press.