HUMAN ONCOPROTEIN MDM2 INTERACTS WITH THE TATA-BINDING PROTEIN IN-VITRO AND IN-VIVO

Human oncoprotein MDM2 inhibits p53-induced transcriptional activation of promoters containing p53-binding sites. In this report we show that MDM2 interacts with the human TATA binding protein (TBP), in vivo and in. vitro, in the absence of p53. The C-terminal boundary of the TBP-binding domain on MDM2 resides between amino acids 221 and 276, whereas the N-terminal boundary is beyond amino acid 120. Thus, the acidic domain of MDM2 overlaps with the TBP binding domain and is needed for the interaction. The C-terminal conserved domain of TBP is required for MDM2 binding. MDM2-TBP interaction suggests a p53-independent, transcription regulatory role of MDM2.