Figure 4.
Inositol-requiring enzyme 1 (IRE1)-dependent induction of pleckstrin homology-like domain, family A, member-3 (PHLDA3). (A) The effect of IRE1 knockdown on PHLDA3 induction. (B) The effect of c-Jun N-terminal kinase (JNK) inhibition on PHLDA3 mRNA, p-c-Jun or p-signal transducer and activator of transcription 3 (STAT3) levels. AML12 cells were exposed to 20 μM JNKi for 1 h and were continuously treated with tunicamycin (Tm) or thapsigargin (Tg). (C) The effects of protein kinase RNA-like endoplasmic reticulum kinase (PERK) or activating transcription factor 6 (ATF6) inhibition. AML12 (left) and HepG2 (right) cells were treated with Tm after transfection with Mock or dominant negative (DN)-PERK construct or with control or ATF6 siRNA. Immunoblottings for p-PERK and ATF6 (90 kDa form) confirmed the effect of DN-PERK and ATF6 siRNA transfection, respectively. For A–C, data represent the mean±SE of three separate experiments. Statistical significance of differences between each treatment group and the control (*p<0.05, **p<0.01) or Tm (#p<0.05) was determined.
