Simian virus 40-specific polypeptides in Ad2+ND4- infected cells

A comparison of the proteins synthesized in human cells at late times after infection with adenovirus (Ad2) and with the adeno-simian virus 40 (SV40) hybrid viruses revealed polypeptides of 30,000 and 92,000 molecular weight specific for the hybrid viruses Ad2+ND1 and Ad2+ND4, respectively. Cell-free translation of SV40-specific mRNA, prepared from these cells by hybridization of total cytoplasmic RNA to SV40 DNA, showed that the mRNA's specifying these two polypeptides were at least partially encoded by the SV40 portion of the hybrid viruses. Cell-free translation of SV40-specific mRNA prepared from monkey cells infected with SV40 produced polypeptides of 40,000, 43,000, 48,500, and 92,000 molecular weight. The SV40 and Ad2+ND4 92,000-molecular-weight polypeptides made in vitro were very similar in electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gels to the polypeptide precipitated by Tegtmeyer (1974) with SV40 anti-T serum.