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. Author manuscript; available in PMC: 2020 May 1.
Published in final edited form as: FEBS Lett. 2019 Apr 30;593(10):1080–1088. doi: 10.1002/1873-3468.13389

Figure 2. Cysteine-832 mediates oxidative stress-induced inhibition of Ire1.

Figure 2.

A) Sequence alignment of the critical region of Ire1 from S. cerevisiae, C. elegans, and humans. Cysteine-832 is highlighted in yellow. Cysteine-748 is highlighted in cyan. Asterisks, identical residues; double dots, highly similar residues; single dots, similar residues.

B-C) The ire1-C832S mutant is refractory to arsenic-induced inhibition of HAC1 splicing, as determined by RT-PCR. HAC1 splicing was induced by either DTT (1.5 mM; panel B) or tunicamycin (5 μg/ml; panel C). Arsenite was used at 1 mM. Treatment was for one hour. Lower panels, ACT1 controls.

D) The ire1-C832S mutant is refractory to arsenic-induced inhibition of transcription of the HAC1 target KAR2, as determined by RT-PCR. Treatment was with tunicamycin (5 μg/ml) and/or arsenite (1 mM) for one hour. Lower panel, ACT1 control. Images were quantitated using NIH Image J, and the relative expression of KAR2 and PGK1 is indicated as a percentage of the respective untreated control.

E) The ire1-C832S mutant is refractory to hydrogen peroxide-induced inhibition of HAC1 splicing, as determined by RT-PCR. HAC1 splicing was induced by tunicamycin (5 μg/ml). Hydrogen peroxide was used at 5 mM. Chemical treatment was for one hour. Lower panel, ACT1 control.