3M-PML forms aberrant nuclear aggregates.

(A) Schematic structure of PML and 3M-PML. Wild-type PML can be modified by SUMO-1 at amino acid positions 65, 160, and 490 through 3 lysines (K). In 3M-PML, the 3 lysines were mutated to arginines (R). R: RING finger domain. B1, B2: B-boxes. Coiled coil: helical coiled-coil region. S/P: serine/proline-rich region. (B) Localization of transfected wild-type PML and 3M-PML. Representative confocal micrographs are shown, with the immunofluorescent colors (PML/3M-PML, red; DAPI, blue) labeled in the lower corners of each image. Bar: 5 μm.