Mutation of the serine 312 phosphorylation site does not alter the ability of mouse p53 to inhibit simian virus 40 DNA replication in vivo.
Two mutations were introduced into the wild-type mouse p53 gene by oligonucleotide-directed mutagenesis. These mutations substituted alanine or aspartic acid for serine at position 312, which is constitutively phosphorylated. Phosphopeptide mapping of the mutant proteins, expressed in COS cells, confirmed the loss of phosphorylation at position 312. There were no changes in the ability of the mutant p53s to express the conformation-dependent epitope for monoclonal antibody PAb246 or to participate in complexes with the simian virus 40 (SV40) large T antigen. Replication of a plasmid containing the SV40 origin of replication was inhibited in COS cells by wild-type p53 and both of the phosphorylation site mutants with equal efficiency. A transforming mutant of p53, encoding valine at position 135, did not inhibit SV40 DNA replication in COS cells.
Meek
D W
DW
Molecular Biology and Virology Laboratory, Salk Institute for Biological Studies, San Diego, California 92138.
Eckhart
W
W
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis*; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000502:physiology; D015513:Oncogene Proteins / Q000235:genetics* / Q000502:physiology; D010750:Phosphoproteins / Q000235:genetics* / Q000502:physiology; D010766:Phosphorylation; D012694:Serine / Q000235:genetics; D013539:Simian virus 40 / Q000235:genetics*; D014162:Transfection; D016159:Tumor Suppressor Protein p53; D014779:Virus Replication
D004279:DNA, Viral; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D010750:Phosphoproteins; D016159:Tumor Suppressor Protein p53; D012694:Serine