FIG. 2.

Schematic representations of Hdm2 or Mdm2 and ARF proteins. (Top) Hdm2 binding sites for p53 and E2F-1 (hatched), ARF and L5 (shaded), and p300 (open) are indicated. Amino acid domains in Hdm2 and Mdm2 required for these associations are indicated by superscripts. The NLS and NES sequences are similarly defined by solid bars. The RING domain (stippled) contains the NrLS (solid bar). (Middle) Shaded areas define the Mdm2 contact sites in mouse ARF; the segment from residues 26 to 37 also contains sequences required for nucleolar localization. (Bottom) The shaded bar defines the mapped Mdm2 binding site in human ARF, which is also required for nucleolar localization. A second NrLS is indicated by the black bar. An additional Mdm2 binding site within human p14^ARF (see text) has not been mapped.