CAR-diology--a virus receptor in the healthy and diseased heart

The interplay of diverse cell-contact proteins is required for normal cardiac function and determines the mechanical and electrical properties of the heart. A specialized structure between cardiomyocytes-the intercalated disk-contains a high density of these proteins, which are assembled into adherens junctions, desmosomes, and gap junctions. The Coxsackievirus-adenovirus receptor (CAR) as a tight junction protein of the intercalated disk has recently been implied in cardiac remodeling and electrical conductance between atria and ventricle. This review summarizes recent in vivo studies that relate CAR to heart disease and how they could translate to improved diagnosis and therapy of viral myocarditis and arrhythmia.