FIGURE 7.

Mutants of FBXW7 are defective in promoting MLST8 degradation and ubiquitination. A, Distribution of the point mutations on the FBXW7 gene found in TCGA pan‐cancer samples. B, 293T cells were transfected with the indicated constructs. After 24 h, cell lysates were prepared for co‐IP assay with anti‐FLAG antibody and WB analyzes. C, FBXW7 W425R increased the half‐life of MLST. The effect of FBXW7 on the half‐life of oncoproteins was determined by Western blot after cells treated with 100 μg/mL cycloheximide (CHX) for 0, 2, 4, and 6 h. D, 293T cells were transfected with wild‐type or mutated FBXW7 constructs as indicated. After 24 h, cell lysates were prepared for WB analysis. E, 293T cells were transfected with the indicated constructs. After 24 h, cells were treated with 20 μmol/L MG132 for 4 h and cell lysates were prepared for immunoprecipitation and WB analysis. F, 293 T cells were cotransfected with indicated Myc‐ FBXW7, HA‐Ub, and Flag‐MLST8. Cells were treated with MG132 for 4 h before harvest. Immunoprecipitated FLAG and Western blot Ub showed the ubiquitination level of MLST8