Figure 2. NAC089 relocates from the ER membrane to the nucleus during ER stress responses.

(A) Topology of NAC089 protein. (B) Activation of MYC-NAC089 in response to ER stress. Plant seedlings were treated with H₂O (control), tunicaymin (TM, 5 µg/ml) or DTT (2 mM) for 6 hr. Star and asterisk represent the precursor and the processed form, respectively. The beta-estradiol (BE) induced truncated form NAC089D-MYC was used as the migration marker. Coomassie blue staining of RbcS serves as the loading control. (C–D) Nuclear relocation of mGFP-NAC089 in response to ER stresses in Arabidopsis leaf protoplast (C) and root cells (D). TM = 5 µg/ml in C and TM = 10 µg/ml in D. Dashed lines highlight the cell boundary. Bar = 50 µm.