[Ryanodine receptor and heart disease]

Calcium ions (Ca2+) play an essential role in cardiac excitation-contraction coupling. Ca2+ is stored in the sarcoplasmic reticulum (SR) and is release via SR-Ca-release channels (ryanodine receptors, RyR2) to trigger contraction. RyR2 is a homotetramer comprising 4 pore-forming subunits. Each subunit is closely associated to regulatory proteins such as calstabine 2 (FKBP12.6), calmodulin, PKA, CamKII, calsequestrin and form a macromolecular complex that plays a critical role in pathological conditions. As a matter of fact, alterations of the channel activity and/or associated regulatory proteins can cause severe functional alterations resulting in arrhythmias and sudden death. Thus, RyR2 represent a novel therapeutic target and the discovery of a new pharmacological agent able to restore a normal RyR2 channel function represents a major challenge in the cardiac field.