Definition of adenovirus type 5 functions involved in the induction of chromosomal aberrations in human cells

Infection of human embryonic kidney cells with adenovirus type 5 (Ad5) induces aberrations (gaps and breaks) in the cell chromosomes. We have conducted a study utilizing a large number of Ad5 mutants to identify the viral functions that are responsible for the occurrence of cytogenetic damage. The results of our investigation have indicated that expression of the gene products of the Ad5 early region 1A (E1A) is necessary for the induction of chromosomal aberrations and that other early viral gene products do not appear to contribute to this phenotype. We have also shown that expression of both the major E1A gene products, the 243 amino acid and the 289 amino acid proteins, is required for induction of damage at wild-type levels, although the 289 amino acid protein appears to retain detectable activity on its own. Lastly, we have observed that deletions in the amino-terminal region of the E1A proteins and in the transactivating domain of the 289 amino acid protein prevent the occurrence of cytogenetic damage, whereas mutations elsewhere in the proteins do not affect this process.