True Molecular Scale Visualization of Variable Clustering Properties of Ryanodine Receptors

• DOI: 10.1016/j.celrep.2017.12.045
• Publication Date: 2018-01-09T16:42:47Z
• Authors: Izzy Jayasinghe; Alexander H. Clow...; Ruisheng Lin; Tobias Lutz; Carl Harrison; Ellen Green; David Baddeley; Lorenzo Di Michele; Christian Soeller
• Keywords: Calcium Signaling

Signaling nanodomains rely on spatial organization of proteins to allow controlled intracellular signaling. Examples include calcium release sites cardiomyocytes where ryanodine receptors (RyRs) are clustered with their molecular partners. Localization microscopy has been crucial visualizing these but limited by brightness markers, restricting the resolution and quantification individual within. Harnessing remarkable localization precision DNA-PAINT (<10 nm), we visualized punctate labeling within nanodomains, confirmed as single RyRs. RyR positions sub-plasmalemmal revealed how they organized randomly into irregular clustering patterns leaving significant gaps occupied accessory or regulatory proteins. RyR-inhibiting protein junctophilin-2 appeared highly concentrated adjacent channels. Analyzing maps showed variations in co-clustering stoichiometry between RyR, even nearby nanodomains. This constitutes an additional level complexity arrangement regulation signaling, intrinsically built