Immunoprecipitation of CaM does not coimmunoprecipitate Ano1 but does coimmunoprecipitate SK2. Flag- and myc-tagged CaM was coexpressed with mAno1(abc), mAno1(ac), or SK2 in HEK 293 cells. Cells were lysed in medium containing EGTA or medium containing Ca²⁺ after treatment with ionomycin to elevate cytosolic Ca²⁺. CaM was immunoprecipitated with anti-Flag antibody. The immunoprecipitate (IP) was subjected to Western blot and probed with antibody to Ano1, SK2, or myc (for CaM). (top) Immunoprecipitate. (bottom) Total lysate. Molecular mass is indicated in kilodaltons. IB, immunoblot.