IDENTIFICATION AND CHARACTERIZATION OF A CDNA CLONE DERIVED FROM THE MAREKS-DISEASE TUMOR-CELL LINE RPL1 ENCODING A HOMOLOG OF ALPHA-TRANSINDUCING FACTOR (VP16) OF HSV-1

We have identified and sequenced a 2.3 kb cDNA clone RPL(N.S) 6 derive d from the Marek's disease virus (MDV)-transformed cell line RPL1, whi ch contained open reading frames (ORFs) homologous to U(L)49 (VP22) an d U(L)48 (VP16) of herpes simplex virus. Northern blot hybridization i dentified a 2.5 kb transcript corresponding to this cDNA clone in the total RNA from MSB1 lymphoblastoid cells, but not in RNA from the orig inal RPL1 cells, most probably due to the very low level of its transc ription. In vitro translation demonstrated that both MDV U(L)49 and U( L)48 can be expressed from a single mRNA.