Functional interaction between the early viral proteins of simian virus 40 and adenovirus

Complementation studies using early temperature sensitive mutants of SV40 and adenovirus suggest that heterologous DNA-protein interactions can occur between these viruses in coinfected cells. This conclusion is based on the following experimental results: (a) The replication defective adenovirus 5 mutant ts125 can grow in African green monkey kidney cells at the nonpermissive temperature in the presence of preinfection with wild type SV40. (b) The overproduction of early SV40 RNA by the early SV40 temperature sensitive mutant tsA58 can be suppressed by superinfection of the monkey cells with wild type adenovirus. (c) The SV40 helper function for the growth of adenovirus in monkey kidney cells can be provided by the early SV40 mutant tsA58, even at the nonpermissive temperature. We suggest that viral DNA-protein cross-reactions may be responsible for these biological phenomena and show by DNA-DNA hybridization under nonstringent conditions (where hybrid DNAs with up to 35% base mismatch will be thermally stable) that certain regions of the Ad2 and SV40 genomes share significant sequence homology.