Multiple transformation phenotypes among revertants of temperature-sensitive mutants in the type 5 adenovirus DNA-binding protein

Seven independently isolated revertants of temperature-sensitive mutants in the 72K protein of Ad5 were tested for the ability to transform rat cells under a variety of conditions. Using the continuous cell line designated CREF, at 36° the range of transformation phenotypes of the different revertants included a frequency characteristic of WT and also the elevated frequency associated with the parental temperature-sensitive alleles. Transformation frequency did not correlate with other phenotypes, such as plaque size or plaquing efficiency on HeLa cells at 38.5°–39°. Therefore, although it is likely that the 72K protein modulates transformation, it is possible to dissociate genetically this regulatory function of the protein from its replicative function in permissive infection.