title: Microarchitecture of the dyad.
abstract: This review highlights recent and ongoing discoveries that are transforming the previously held view of dyad structure and function. New data show that dyads vary greatly in both structure and in their associated molecules. Dyads can contain varying numbers of type 2 ryanodine receptor (RYR2) clusters that range in size from one to hundreds of tetramers and they can adopt numerous orientations other than the expected checkerboard. The association of Ca(v)1.2 with RYR2, which defines the couplon, is not absolute, leading to a number of scenarios such as dyads without couplons and those in which only a fraction of the clusters are in couplons. Different dyads also vary in the transporters and exchangers with which they are associated producing functional differences that amplify their structural diversity. The essential role of proteins, such as junctophilin-2, calsequestrin, triadin, and junctin that maintain both the functional and structural integrity of the dyad have recently been elucidated giving a new mechanistic understanding of heart diseases, such as arrhythmias, hypertension, failure, and sudden cardiac death.
authors: Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3.
authors: David R L
authors: DR
authors: Scriven
authors: Parisa
authors: P
authors: Asghari
authors: Edwin D W
authors: ED
authors: Moore
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000502:physiology; D002155:Calsequestrin / Q000502:physiology; D056966:Excitation Contraction Coupling; D006801:Humans; D008565:Membrane Proteins / Q000502:physiology; D032383:Myocytes, Cardiac / Q000648:ultrastructure*; D019837:Ryanodine Receptor Calcium Release Channel / Q000502:physiology; D012508:Sarcolemma / Q000648:ultrastructure*; D012519:Sarcoplasmic Reticulum / Q000648:ultrastructure*; D019831:Sodium-Calcium Exchanger / Q000502:physiology
chemical_list: D020746:Calcium Channels, L-Type; D002155:Calsequestrin; C419385:L-type calcium channel alpha(1C); D008565:Membrane Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D019831:Sodium-Calcium Exchanger; C412507:junctophilin; D002118:Calcium