Figure 4: REM activation of JNK inhibits YB-1-dependent MDR1 expression. (a-b) MCF-7/Dox cells were transfected with MDR1-luc and constructs indicated for 24 hours. REM ± SP600125 was treated for 6 hours. Assays were performed in triplicate, and value less than 0.05 (marked with an asterisk, *) was considered statistically significant. (c) YB-1 interaction with pJNK1/2. Cytosolic and nuclear proteins were immunoprecipitated with anti-YB-1 antibody. The immunoprecipitants and input proteins were then blotted with the antibodies for pJNK1/2, YB-1, JNK1, and actin. Asterisks indicate heavy chains from the immunoprecipitation. Quantitative analyses of protein interactions were performed using the Image J software.