Fig. 3.

17-Aminogeldanamycin (AG) at 0.4 μM transiently increases mRNA levels of HSP70 and GRP78, and inhibits IRE1α-dependent pathway of UPR a, b HSP70 and GRP78 transcript levels were assessed by qRT-PCR after 6 and 22 h, and expressed relatively to the control. *p ≤ 0.05 c GRP78 protein level was determined by Western blotting after 4 and 24 h. An equal loading was confirmed by β-actin. Quantification of the protein level is shown below the blots. d Levels of active (phosphorylated IRE1α; p-IRE1α) and total IRE1α were determined after 4 and 24 h. β-actin was used as a loading control. Quantifications of p-IRE1α and IRE1α levels are shown below the blots. e XBP1 s transcript level after 22 h is shown relatively to the control. *p ≤ 0.05 f Activity of ATF6 was determined as the level of ATF6 cleavage product (p50) after 4 and 24 h. An equal loading was confirmed by β-actin. Quantification of the protein level is shown below the blots. g The transcript levels of CHOP and BIM were assessed by qRT-PCR after 22 h, and expressed relatively to the control. *p ≤ 0.05