Optical single-channel resolution imaging of the ryanodine receptor distribution in rat cardiac myocytes

• DOI: 10.1073/pnas.0908971106
• Publication Date: 2009-12-16T04:19:30Z
• Authors: David Baddeley; Izzy Jayasinghe; Leo Lam; Sabrina Rossberger; Mark B. Cannell; Christian Soeller
• Keywords: Calcium Signaling

We have applied an optical super-resolution technique based on single-molecule localization to examine the peripheral distribution of a cardiac signaling protein, ryanodine receptor (RyR), in rat ventricular myocytes. RyRs form clusters with mean size approximately 14 per cluster, which is almost order magnitude smaller than previously estimated. Clusters were typically not circular (as assumed) but elongated average aspect ratio 1.9. Edge-to-edge distances between adjacent RyR often <50 nm, suggesting that may exhibit strong intercluster signaling. The wide variation cluster size, follows near-exponential distribution, compatible stochastic assembly process. suggest calcium sparks be result concerted activation several forming functional “supercluster” whose gating controlled by both cytosolic and sarcoplasmic reticulum luminal levels.