ISOLATION AND IDENTIFICATION OF THE HUMAN HOMOLOG OF A NEW P53-BINDING PROTEIN, MDMX

We recently reported the identification of a mouse cDNA encoding a new p53-associating protein that we called Mdmx because of its structural similarity to Mdma, a well-known p53-binding protein. Here are report the isolation of a cDNA encoding the human homolog of Mdmx. The ORF o f the cDNA encodes a protein of 490 amino acids, 90% similar to mouse Mdmx. The homology between Mdmx and Mdma is most prominent in the p53- binding domain and the putative metal-binding domains. The Mdmx protei n, which, based on SDS-PAGE, has a MW of 80 kDa, can bind p53 in vitro . The human MDMX gene is transcribed in all tissues tested, with high levels in thymus. By fluorescence in situ hybridization analysis we ma pped the mouse mdmx gene to chromosome 1 (region F-G) and the human MD MX gene to chromosome 1q32. (C) 1997 Academic Press.