TRIM26 promotes PBX1 degradation in proteasomes. (A) Flag-PBX1 and increased Myc-TRIM26 plasmids were co-transfected into HEK293T cells for 48 hrs, and then cell lysates were subjected to immunoblotting assay. (B) Myc-PBX1 and Flag-TRIM26 plasmids were co-transfected into HEK293T cells for the indicated periods followed by immunoblotting assay. (C) Flag-PBX1, Myc-TRIM26 or Myc-TRIM26-∆R plasmids were co-transfected into HEK293T cells for 48 hrs, and then cell lysates were subjected to immunoblotting assay. (D) Flag-TRIM26 plasmids were transfected into A549 or H226 cells for 48 hrs, and then cell lysates were subjected to immunoblotting assay. (E) siTRIM26 sequences were transfected into A549 and H226 cells for 48 hrs, followed by cell lysate preparation and IB assays as indicated. (F) Myc-TRIM26 or Myc-TRIM26-∆R plasmids were transfected into A549 or H226 cells for 48 hrs, and then cell lysates were subjected to immunoblotting assay. (G, H) A549 cells were transfected with TRIM26 plasmids for 48 hrs, followed by the treatment with proteasome inhibitors (G) or lysosome inhibitors (H) treatment followed by immunoblotting assay. (I) A549 cells were subjected to transfection of siTRIM26, (J) H226 cells were transfected with TRIM26 plasmids, 36 hrs later cells were incubated with cycloheximide (CHX) for indicated periods before being collected for IB assays.