Ca2Â + channel and Na+/Ca2Â + exchange localization in cardiac myocytes

► We examine the structural determinants of Cav1.2 localization. ► The localization and multiple functional roles of NCX and Cav1.2 are reviewed. ► Couplons exhibit a variety of molecular architectures. ► Couplon function and regulation varies with their molecular occupants. ► We end with a series of important, unanswered, questions.