A. HEK293 cells were transfected with a Cx43-EGFP plasmid, cells harvested 48 h after transfection, lysates subjected to immunoprecipitation (IP) with anti-EGFP antibody, and the Western blot probed with the respective anti-MKK4, -MKK7, -JNK, -cSrc, or anti-ASK1 antibodies. B. Same as above but in cells transfected (Tx) with both ASK1 and Cx43-EGFP (left) or EGFP (right). In: input lysate approximately 1:10 of the protein amount used for IP, -: no IP antibody control, +: with IP antibody. Representative of 3 independent experiments.