Specific DNA binding activity of T antigen subclasses varies among different SV40-transformed cell lines.
Large tumor antigen (T antigen) occurs in at least three different oligomeric subclasses in cells infected or transformed by simian virus 40 (SV40): 5-7 S, 14-16 S, and 23-25 S. The 23-25 S form is complexed with a host phosphoprotein (p53). The DNA binding properties of these three subclasses of T antigen from nine different cell lines and free p53 protein were compared using an immunoprecipitation assay. All three subclasses of T antigen bound specifically to SV40 DNA sequences near the origin of replication. However, the DNA binding activity varied between different cell lines over a 40- to 50-fold range. The 23-25 S and 14-16 S forms from most of the cell lines tested bound much less SV40 origin DNA than 5-7 S T antigen. The free p53 phosphoprotein did not bind specifically to any SV40 DNA sequences.
D000818:Animals; D000956:Antigens, Viral / Q000145:classification; D000957:Antigens, Viral, Tumor; D001483:Base Sequence; D002472:Cell Transformation, Viral; D006224:Cricetinae; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism*; D000882:Haplorhini; D006801:Humans; D051379:Mice; D010750:Phosphoproteins / Q000378:metabolism; D013539:Simian virus 40 / Q000276:immunology / Q000502:physiology*; D016159:Tumor Suppressor Protein p53
D000956:Antigens, Viral; D000957:Antigens, Viral, Tumor; D004279:DNA, Viral; D010750:Phosphoproteins; D016159:Tumor Suppressor Protein p53