A novel mRNA and a low molecular weight polypeptide encoded in the transforming region of adenovirus DNA.

Immunoprecipitation was used to identify adenovirus type 2 (ad2) tumor antigens synthesized in vivo. The antisera, prepared from tumor-bearing animals, reacted with a wide spectrum of ad2 early proteins including a 11 000-dalton (11 K) polypeptide. The gene for this polypeptide was mapped to the transforming region of the viral genome by hybridization selection followed by in vitro translation and immunoprecipitation. Hybrid arrest translation revealed that the 11 K RNA was transcribed from the leftward reading strand (1-strand) in contrast to other mRNAs from this region. Sucrose gradient analysis of the selected 11 K mRNA revealed that the size of the mRNA was 20S corresponding to approximately 2000 nucleotides. Novel 1-strand transcripts of this length from the transforming region were identified by S1 endonuclease analysis. Taken together, these results suggest that both strands of the transforming region of ad2 DNA are actively transcribed into functional mRNA early after viral infection.