Anti-apoptotic role of the IRE1–XBP1 pathway that counteracts the pro-apoptotic IRE1–JNK.

<p>(A–G) Cells were transfected with empty vector and IRE1αΔRNase (A–C), dominant-negative mutant of XBP1 (XBP1-DN) (D, E) or XBP1(S) (F, G), treated with Cd for 6 hr (A) or 60 hr (B–G) and subjected to Western blot analysis of nuclear XBP1 (A), trypan blue analysis (B, D, F) and assessment of procaspase-3 cleavage (C, E, G). (H, I) Cells were co-transfected with XBP1(S) and siTSC2, treated with Cd for 60 hr, and subjected to trypan blue analysis (H) and Western blot analysis of caspase-3 (I).