Fig. 3.

Co-immunoprecipitation (co-IP) experiments in HeLa cells. Ubiquitinated SMN protein was determined by co-IP using 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). SMN ubiquitination 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 at the mock status (not treated with salbutamol) was normalized to 1.0 in each MG132 group (in the presence or absence of MG132). The mean ubiquitinated SMN amount decreased by 20–30 percent after salbutamol treatment.