Figure S1.

Wild-Type ERdj4 Rescues ΔERdj4, Related to Figure 1

(A) Plot of tunicamycin (Tm) concentration-dependent changes in XBP1s::Turquoise and CHOP::GFP reporter gene activity in wild-type CHO cells. Shown is the median fluorescence value (normalized to the untreated sample) obtained from 10,000 cells in experimental triplicates and the fit to a sigmoidal dose-response curve.

(B) Dual channel flow cytometry plots of the XBP1s::Turquoise reporter and mCherry (a transfection marker) in wild-type and ΔERdj4 cells transiently transfected with a mCherry-tagged plasmid encoding no ERdj4 (“empty”), wild-type ERdj4 and mutant ERdj4^QPD. The red rectangle delineates the gate used to select cells expressing moderate levels of mCherry-tagged plasmid for the histogram shown in Figure 1C.

(C) XBP1s::Turquoise and CHOP::GFP signals from cells of the indicated genotype (wild-type, WT or ΔERdj4) transfected with ER-localized mCherry (ER-mCherry, a control) or mCherry tagged full-length ERdj4 (ERdj4-mCherry), mCherry tagged ERdj4 isolated J domain (1-90) (J4-mCherry; WT and QPD, lacking the C-terminal targeting domain). Transfected cells were gated for moderate mCherry expression as in (B) above.

(D) XBP1s::Turquoise signals from wild-type or ΔERdj4 cells. Where indicated, cells were treated with tunicamycin (Tm) or the IRE1 inhibitor 4μ8c.