Fig. 3.

Inhibition of MEF2A activity by ubiquitination. (a) SN4741 cells were transfected with constructs for MEF2 luciferase reporter (mt: MEF2 site mutated, wt: MEF2 site intact) alone or with Flag-MEF2A and HA-Ub as indicated. Luciferase activity was measured 24 hours later. The luciferase activity from cells transfected with wt MEF2 reporter alone was set as 100%. The experiments were repeated 5 times (n=5). (b) SN4741 cells were treated with MG132 (2.5 μM), MPP⁺ (25 μM) and rotenone (100 nM) for 6 hours. MEF2 reporter assay was carried out as in (a). The experiments were repeated 5 times (n=5). (c) SN4741 cells were treated as described in (b). MEF2 DNA-binding activity in whole cell lysates were tested by EMSA assay. The experiments were repeated 3 times. The quantification of DNA-binding activity was shown on the left-bottom graph. *, p<0.01.