FIGURE 3.

Nondenaturing PAGE to check for complex formation between CaM and the Ca_V1.1 (Sk) or Ca_V1.2 (Card) C-terminal regions CT1, CT2, and CT3 (see Fig. 1 for orientation). In the presence of 2 mm Ca²⁺, all CTs of the cardiac type were able to form a complex with CaM (underlined labels; confirmed for CT1 by mass spectrometry), whereas the skeletal type CT constructs lacked the additional band. In the absence of Ca²⁺ and presence of 2 mm EDTA, CaM failed to form a complex with cardiac (or skeletal) CT1 (bottom, right).