Fig. 7

Depletion of Smurf2 accelerates degradation of CNKSR2. a Serum starved HEK293 cells were treated with MG132 at the indicated doses and time intervals and expression of CNKSR2 was assessed using western blot indicating proteasome mediated degradation of CNKSR2. b Decline in CNKSR2 expression induced by Smurf2 siRNA was rescued by treating the cells for 4 h with 10 μM MG132 44 h post-transfection. c Depletion of Smurf2 results in enhanced polyubiquitination and proteasomal degradation of CNKSR2. CNKSR2 was immunoprecipitated from MDA-MB-231 cells transfected with Smurf2 siRNA and control siRNA. Cells were treated for 4 h with 10 μM MG132 44 h post-transfection. The corresponding lysates were denatured and immunoprecipitated (IP) with rabbit CNKSR2 antibody, followed by Western blotting (IB) of the immune complexes with a mouse anti-ubiquitin antibody. The input proteins in cell lysates were also probed by the indicated antibodies