Figure 3. Effect of proteasome inhibitors on the half life of Cx43 following phosphorylation

A: LEC were labeled with ³⁵S for 1 h either in the presence or absence of 40 μM MG132. For the last 30 min of labeling, cells were treated with 50 ng/ml TPA. For controls, cells were metabolically labeled in the absence of TPA and MG132. The cells were chased for 1 h with non-labeled medium and Cx43 was immunoprecipitated using polyclonal antibodies against Cx43. Immunoprecipitated proteins were separated by SDS-PAGE and autoradiographed. B: Quantification of the amount of ³⁵S labeled Cx43 after 1 h of chase using a PhosphorImage analyser, Storm 860. Data represents the average with standard deviation of three independent experiments.