MDM2 is an important negative regulator of the p53 tumor suppressor. The protein functions both as an E3 ubiquity lipase that recognizes the N-terminal trans-activation domain(TAD) of the p53 tumor suppressor and an inhibitor of p53 transcriptional activation. Oliner et al.(1992) used MDM2 clones to localize the human gene to chromosome 12q13-q14 by analysis of human-hamster somatic cell hybrids.
