Characterization of the binding sites for the interactions between FKBP12 and intracellular calcium release channels

► Prolyl-dipeptide motifs in calcium channels, such as RyR1, RyR3 and IP3R1, but not RyR2, bind to FKBP12. ► Important binding residues in FKBP12 are located in its hydrophobic FK506 binding cleft. ► FK506 can competitively inhibit the interaction between FKBP12 and the dipeptide motifs of the calcium channels.