Skip to main content
. Author manuscript; available in PMC: 2014 Nov 1.
Published in final edited form as: Pigment Cell Melanoma Res. 2013 Sep 9;26(6):10.1111/pcmr.12158. doi: 10.1111/pcmr.12158

Figure 2. Oca2-null melanocytes are more resistant to thapsigargin-induced ER stress, and show disruption of Perk signaling at the eIF2α level upon treatment.

Figure 2

(a) Wildtype and Oca2-null melanocytes were treated with 150 nM thapsigargin (TG) for 48 h, following which a crystal violet assay was performed in order to assess viability. Average viability ± SEM is shown as percentage compared to vehicle-treated controls (n = 3). *P<0.05. (b) Melanocytes were treated with 150nM TG for either 4 h or 10 h and allowed to recover in fresh medium. A crystal violet assay was performed at either day 2 or day 8. (c-e) Cells were treated with 150 nM thapsigargin for the indicated times, followed by protein extraction and immunoblot analysis of molecules involved in Ire1 and Perk signaling. Phosphorylation of Perk increases protein mass resulting in slower migration during SDS-PAGE; cParp= cleaved Parp. RNA was extracted for reverse transcriptase PCR analysis of Xbp-1 mRNA splicing. Xbp1-u= unspliced Xbp-1; Xbp1-s=spliced Xpb-1. (f) Cells were treated with 150 nM thapsigargin or 10 μg/ml tunicamycin for 6 hours, followed by protein extraction and immunoblot analysis of phosphorylated eIF2α.