Mapping of the p53 and mdm-2 interaction domains.
The 90-kDa cellular protein encoded by the mouse mdm-2 oncogene binds to the p53 protein in vivo and inhibits its transactivation function (J. Momand, G. P. Zambetti, D. C. Olson, D. George, and A. J. Levine, Cell 69:1237-1245, 1992). cDNA clones encoding the human homolog of the mdm-2 protein (also called hdm-2) were isolated from a HeLa cell cDNA library. A series of monoclonal antibodies have been generated against human mdm-2 protein, and the epitopes recognized by these antibodies have been mapped. By construction of a series of deletion mutants, the region of the mdm-2 protein that is critical for complex formation with the p53 protein has been mapped to the N-terminal portion of the human mdm-2 protein. Interestingly, a monoclonal antibody with an epitope located in this same region failed to immunoprecipitate the mdm-2-p53 complex and appeared to recognize only free mdm-2 protein. The domain of the p53 protein that is sufficient for interaction with human mdm-2 protein has been mapped to the N-terminal 52 amino acid residues of the p53 protein. This region contains the transactivation domain of p53, suggesting that mdm-2 may inhibit p53 function by disrupting its interaction with the general transcription machinery.
Chen
J
J
Department of Molecular Biology, Princeton University, New Jersey 08544-1014.
Marechal
V
V
Levine
A J
AJ
D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins; D009857:Oncogenes; D011518:Proto-Oncogene Proteins; D051736:Proto-Oncogene Proteins c-mdm2; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA; C497206:MDM2 protein, human; C497207:Mdm2 protein, mouse; D051736:Proto-Oncogene Proteins c-mdm2