A,
ERK knockdown by siRNA was performed in VACO432 (BRAFV600E/WT), as well as isogenic VACO432 VT1 (BRAFWT/−) cells with ectopic BRAFV600E vs empty vector (EV). Protein expression was determined by immunoblotting. B, Ectopic expression of HA-tagged wild type (WT) MCL-1, and phosphorylation-mimicking [T92D/T163D (DD)] or unphosphorylated [T92A/T163A (AA)] MCL-1 mutants was performed in HT29 cells. C, Cell lines were treated with cycloheximide (5 mmol/L) for the indicated times and protein expression against HA-tagged MCL-1 was analyzed by immunoblotting. The level of MCL-1 expression was then quantified by densitometry and normalized using tubulin expression.