Fig. 5
KDM8 promotes the nuclear translocation and transactivation activity of allostery-insensitive PKM2 variants. a, b MCF7 cells were transfected with HA-PKM2s (wild-type, R399E, H391Y, and G415R) or co-transfected with HA-PKM2 plus Flag-KDM8, followed by staining with anti-HA (HA-PKM2, green) and anti-Flag (Flag-KDM8, magenta). Representative images of the nuclear translocation of PKM2 in wild-type-PKM2-expressing cells in the absence or presence of KDM8 are shown in a. Arrowheads indicate the cells with detectable nuclear localization of PKM2. Bar 20 μm. The mean percentage of nuclear-localized PKM2 cells over PKM2-expressing cells from three preparations (n ≥ 50) for each PKM2 type (wild-type, R399E, H391Y, and G415R) was determined as shown in b (wild-type vs. R399E, p = 0.043; wild-type vs. H391Y, p = 0.040; wild-type + KDM8 vs. H391Y + KDM8, p = 0.015). c MCF7 cells were transfected with HA-PKM2s with or without knocking down endogenous KDM8 as indicated. Cells were then fractionated followed by Western blotting analysis. Histone H3 and α-tubulin were used as the marker for nucleus and cytosol, respectively. d Nuclear transactivation activity (wild-type vs. R399E, p = 0.013; wild-type vs. H391Y, p = 0.011; G415R vs. G415R + KDM8, p = 0.034). Statistical significance was evaluated using the two-tailed t-test. *p < 0.05; **p < 0.01; ***p < 0.001; n.s., p > 0.05; LKO, pLKO shRNA control. Bar plots are shown in mean ± SD. WT, wild-type
