Analysis of virus-specific mRNAs present in cells transformed with restriction fragments of adenovirus type 5 DNA.

Summary Adenovirus type 5 (Ad5) mRNAs present in cells transformed with left-terminal Ad5 DNA fragments (XhoI-C, 0 to 15.5%; HindIII-G, 0 to 7.7%; HpaI-E, 0 to 4.3% were characterized by ‘Northern blotting’ and S1 nuclease analysis. They were compared with the mRNAs transcribed from the Ad5 E1 region in the early and late stages of lytic infection. It is shown that in XhoI-C-transformed cells the same mRNAs were transcribed as early during lytic infection: two co-terminal mRNAs from region E1a, differing only in their splicing, and one major E1b transcript. In HindIII-G-transformed cells additional E1a mRNAs were detected with a novel 5′ terminus, but with the normal splicing pattern. Instead of the normal E1b mRNA, HindIII-G-transformed cells were found to contain mRNAs consisting of a viral E1b segment and a non-viral segment. This E1b-encoded segment was shown not to be involved in RNA splicing. The mRNAs in cells transformed with Ad5 HpaI-E were similar to the E1a mRNAs found in XhoI-C- and HindIII-G-transformed, and in lytically infected cells but had aberrant 3′ termini. These results are discussed in the light of the Ad5 E1 DNA and RNA sequences, and protein mapping data.