Cells were co-transfected with BKCa, BKCa-DEC and ANT in different combinations (+, present; -, absent). (A) BKCa and BKCa-DEC were immunoprecipitated with anti-BKCa mAb and detected with anti-BKCa pAb (top panel); coimmunoprecipitated ANT was detected with anti-Flag pAb that recognizes the DDK epitope (lower panel, squares). Top and bottom panels are different blots using the same immunoprecipitation products. (B) Input lysates showing proper expression of BKCa (top panel) and ANT (lower panel). BKCa and BKCa-DEC were detected with anti-BKCa pAb and ANT was detected with anti-Flag pAb. (C) Mean values of BKCa and BKCa-DEC efficiency in pulling down ANT show that BKCa-DEC associates better with ANT by about 30%. Co-immunoprecipitation efficiency was calculated as described in the legend to Figure 2 for Tom22. **, p<0.01 , n=3 independent experiments.