Fig. 5.

DDX39B promotes ERK-independent PKM2 nuclear translocation. a Nuclear and cytosolic protein lysates prepared from HCT116 and SW620 cells stably expressing mock or DDX39B were assayed by western blotting. b The subcellular localization of PKM2 in HCT116 and SW620 cells stably expressing mock or DDX39B was visualized by immunofluorescence assay. c Phosphorylation of PKM2^S37 and ERK1^T202/Y204, ERK2^T185/Y187 in CRC cells stably expressing mock or DDX39B was detected by western blotting. d The indicated CRC cells were cotransfected with Flag-DDX39B and Myc-PKM2^WT or Myc-PKM2^S37A, and immunofluorescence assay was performed. e The CRC cells were cotransfected as indicated, and the binding of importin α5 to PKM2^WT or PKM2^S37A was evaluated by immunoprecipitation assay. f DDX39B-knockdown CRC cells were treated with or without 150 ng/ml EGF, and the association of importin α5 with PKM2 was detected by immunoprecipitation assay. g Lysates prepared from CRC cells cotransfected with Flag-DDX39B and HA-PKM2 were subjected to tandem affinity purification using anti-Flag and anti-HA magnetic beads. h In vitro binding analysis was performed using the indicated purified proteins. i DDX39B and PKM2 protein levels in serial sections of CRC tissues (n = 42) were measured by immunohistochemistry staining. j The correlation of relative staining intensities between DDX39B and PKM2. k The association of DDX39B and nuclear PKM2 in CRC tissues. The p values were determined by Pearson correlation coefficient analysis (j) or Student’s t test (k). **p < 0.01