COMPARISON BETWEEN E1A GENE FROM ONCOGENIC AND NONONCOGENIC ADENOVIRUSES IN CELLULAR-TRANSFORMATION (ADE1A CONSERVED REGION)

All adenoviruses transform primary BRK cells in vitro, but only cells transformed by oncogenic adenoviruses are tumorigenic for immunocompet ent animals. The transforming E1 regions of human Ad 2 and Ad 12 also differ from each other in the frequency in which they can transform BR K cells. We have investigated these properties which can be assigned t o the specific domain of the E1A region. For this purpose, chimeric EI A regions between Ad 2 and Ad 12 have been constructed. The efficiency of cell transformation appeared to be determined by the encoding regi on. The promoter sequences were not important for an efficient cellula r transformation although the E1B region cis activated in E1A transcri ption in both cell transformation and transient expression. We show th at sequences located in the E1B promoter were responsible for this eff ect. In the encoding region the CR 1 domain was essential for the cell transformation frequency.