FIG. 2.

Mta increases BMRF1 protein expression. Western analysis was used to determine BMRF1 protein levels in Vero cells transfected with BMRF1 expression vectors that provide a heterologous strong promoter and use either natural 3′ downstream sequences (pMH2) or vector-provided splicing and 3′ processing signals (pRTS14). BMRF1 protein was detected with anti-BMRF1 MAb, and the actin control was detected on a duplicate membrane with antiactin MAb. In the presence of Mta (+), the amount of BMRF1 protein was increased in cells transfected with either vector. However, expression from pMH2 was dependent on Mta, and no BMRF1 protein was detected in the absence of Mta (−).