Co-immunoprecipitation (co-IP) experiments in HeLa cells. The ubiquitinated SMN protein was determined by co-IP using an anti-SMN antibody. (A) Ubiquitinated SMN extracted by co-IP. HeLa cells were incubated with salbutamol sulfate (20 µM) for 24 h in the presence or absence of the proteasome inhibitor, MG132 (5 µM). The ubiquitination of SMN was reduced in HeLa cells treated with salbutamol, in the presence or absence of MG132. (B) Quantification of ubiquitinated SMN levels.
The amount of ubiquitinated SMN in the sham state (not treated with salbutamol) was normalized to 1.0 in each MG132 group (in the presence or absence of MG132). The mean amount of ubiquitinated SMN decreased by 20-30% after salbutamol treatment.