Fig. 10. Altered expression of Cx43 in ROS/ZO-1myc cells. (A) ROS cells and transfected ROS cells were solubilized in 1% SDS. Equal aliquots of protein were analyzed by immunoblotting with a Cx43 antibody. (B) Cx43 associates with ZO-1myc in the ROS/ZO-1myc cells. Cx43-associated proteins were isolated from lysates derived from ROS/ZO-1myc cells using our co-immunoprecipitation protocol. Immunoblotting with the anti-myc monoclonal antibody identified ZO-1myc in the immunoprecipitates derived from ROS/ZO-1myc cells. (C) Cells were incubated 1 ml of PBS containing 100 µg/ml NHS-LC-biotin and solubilized in lysis buffer. The biotinylated proteins were isolated with Neutravidin agarose (Pierce). The resins were extensively washed and the bound material was analyzed by immunoblotting with Cx43 antiserum.