Fig. 1

The methyltransferase complexes MLL1/WDR5 interact with SOX2. a SOX2 was a short-lived protein. SOX2 protein was rapidly decreased upon inhibition of cellular protein synthesis by cycloheximide (CHX, 100 μg mL⁻¹). Unrelated protein Cullin-1 was blotted as a loading control. Densitometry measurements of blots illustrated the relative protein level of SOX2 upon CHX treatments. b Inhibiting the activity of 26S proteasome promoted the accumulation of SOX2. PA-1 cells were incubated with 5 μg mL⁻¹ MG-132 as indicated, and harvested for western analysis. The data in a and b were represented as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001. c SOX2 physically interacts with the MLL1/WDR5 complexes. PA-1 cells were treated with MG-132 for 3 h, and then subjected to co-immunoprecipitation using antibodies against WDR5, RBBP5, SOX2, and NRS (normal rabbit serum as a control). The interactions between SOX2 and WDR5, RBBP5, ASH2L, and MLL1 were examined by western blotting