title: mlt Mutation in the polyomavirus genome impairing a function of the middle T protein.
abstract: The DNA from polyomavirus mlt mutant P155 transforms cells in culture as efficiently as wild-type DNA but has a much lower tumorigenic potential when injected into newborn rodents. The mutant has a 12-base-pair deletion between nucleotides 1347 and 1360, i.e., in a region which encodes parts of the middle and large T antigens (G elinas et al., J. Virol. 43:1072-1081, 1982). To determine which of the two viral gene functions was affected by the mutation, we transferred the latter into a modified polyomavirus genome encoding exclusively the middle T protein. Our results show that the P155 mutation alters a function of the polyomavirus middle T protein required for the induction of the tumorigenic process in vivo. Beside the 12-base-pair deletion at 96.3 map units, there is no other alteration in the coding sequence of P155 middle T with respect to that of P16, the wild-type parental strain. We conclude, therefore, that the deletion is the lesion affecting the tumorigenic potential of mutant P155 .
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming; D001483:Base Sequence; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D006224:Cricetinae; D004279:DNA, Viral / Q000032:analysis*; D009154:Mutation; D009857:Oncogenes; D011120:Polyomavirus / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral; D014764:Viral Proteins