(A) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, Myc-Smad7, and shPKM2. (B) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, Myc-Smad7, and Flag-PKM2 (WT or K305Q). (C) 293T cells were transfected with SMAD7 siRNA, then transfected with GFP-TβR1 and Flag-PKM2, and immunoprecipitated with anti-GFP antibody. (D) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, Myc-Smad7, and increasing concentrations of Flag-PKM2. (E) Luciferase assay in 293T cells transfected with the CAGA-luc reporter, Myc-Smad7, and increasing concentrations of Flag-PKM2. (F) Luciferase assay in 293T cells transfected with the CAGA-luc reporter, HA-TβR1, Myc-Smad7, and Flag-PKM2. (G) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, HA-ubiquitin, and shPKM2. Cells were treated with MG132 for 4 hours before harvest. (H) Immunoprecipitation with anti-GFP antibody in 293Tcells transfected with GFP-TβR1, HA-ubiquitin, and Flag-PKM2 (WT or K305Q). Cells were treated with MG132 for 4 hours before harvest. (I) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, HA-ubiquitin, and shPKM2. Cells were treated with MG132 for 4 hours before harvest. (J) Immunoprecipitation with anti-GFP antibody in 293T cells transfected with GFP-TβR1, HA-ubiquitin, and Flag-PKM2. Cells were treated with MG132 for 4 hours before harvest. Data are represented as the means ± SEM. *P < 0.05; ****P < 0.00001, Student’s t test.