EF-hand and pre-IQ-IQ domains are the minimal determinants in the CTD that disable CDF in Ca_v2.2. (A–F) As in Fig. 5 B except cells transfected with Ca_v2.2 channels containing EF-hand, pre-IQ-IQ, or CBD of Ca_v2.1 (A–C) or Ca_v2.1 channels containing corresponding regions of Ca_v2.2 (D–F). Data represent mean ± SEM.