Dimerization of MLL fusion proteins and FLT3 activation synergize to induce multiple-lineage leukemogenesis
J. Clin. Invest. Ryoichi Ono, et al. 115:919 doi:10.1172/JCI22725 [Go to this article.]

Figure 3
Oligomerization of MLL-SEPT6 fusion protein through both its GTP-binding domain and its coiled-coil region in the nucleus. 293T cells were cotransfected with equal amounts of FLAG-tagged and HA-tagged constructs (A), and transfected with pMXs-neo-SEPT6 or pMXs-neo-MLL-SEPT6 (B). (A) Self-interaction among MLL-SEPT6 fusion proteins or MLL-SEPT6 mutants, analyzed by Western blot analysis after immunoprecipitation. Lysates of 293T cells coexpressing FLAG-tagged and HA-tagged MLL-SEPT6 or its mutants (top and middle) were immunoprecipitated by the anti-FLAG Ab, and lysates of the cells expressing HA-tagged MLL-SEPT6 or its mutants (bottom) were immunoprecipitated by the anti-HA Ab. Anti-FLAG immunoprecipitates were blotted with the anti-HA Ab (top) or the anti-FLAG Ab (middle), while anti-HA immunoprecipitates were blotted with the anti-HA Ab (bottom). Lane 1, MLL-SEPT6; lane 2, MLL-SEPT6^Δcoil; lane 3, MLL-SEPT6^ΔP-loop; lane 4, MLL-SEPT6^S56N. (B) Localization of SEPT6 and MLL-SEPT6, analyzed by immunofluorescent confocal microscopy. FITC-conjugated secondary Abs reacting with the anti-FLAG Ab in 293T cells expressing SEPT6 or MLL-SEPT6 visualized their cellular localizations (middle). Nuclei were visualized with DAPI (left), and merged images are displayed (right). Original magnification, ×400.