Figure 1.

MDMX forms a complex with 14-3-3. (A) Copurification of 14-3-3 with MDMX. HeLa cells stably transfected with FLAG-MDMX were immunoprecipitated using anti-FLAG M2 antibody, the purified MDMX and associated proteins were detected by Coomassie stain. The two marked bands were identified as CK1α and 14-3-3τ by mass spectrometric peptide sequencing. (B) Interaction of endogenous 14-3-3 and MDMX. MCF7 cells were treated with 30 μM MG132 for 4 h, 0.5 μM camptothecin for 16 h, or irradiated with 10 Gy γ irradiation for 4 h. Cell lysates were immunoprecipitated with MDMX antibody 8C6, followed by anti-14-3-3τ Western blot. (C) Interaction of MDMX with 14-3-3 isoforms. H1299 cells transiently cotransfected with MDMX and epitope-tagged 14-3-3 plasmids were immunoprecipitated using anti-FLAG (for τ, σ, γ), anti-myc (for ζ, β), and anti-His6 (for ɛ, η) antibodies.