Figure 3

HIPK2 is involved in β-catenin proteasomal downregulation. (A) 293 cells were co-transfected with HA-β-catenin or HA-S33Y β-catenin mutant along with increasing amount (1, 3, 5 μg) of HIPK2 expression vector. Thirty-six hours after transfection, total cell extracts were separated on denaturing SDS-PAGE and analyzed by immunoblotting (IB) with anti-HA antibody (to detect β-catenin) and anti-tubulin (as protein loading control). (B, C) 293 cells were transfected with HA-β-catenin and HIPK2 or K221R expression vectors in the presence or absence of the proteasome inhibitor MG132 (2.5 μM) for 6 h and analyzed by immunoblotting with anti-HA (to detect β-catenin), anti-cyclin D1, and anti-tubulin (as protein loading control) antibodies.