TY - JOUR T1 - Single-molecule localization of Na<sub>v</sub>1.5 reveals different modes of reorganization at cardiomyocyte membrane domains JF - bioRxiv DO - 10.1101/674275 SP - 674275 AU - Sarah H. Vermij AU - Jean-Sébastien Rougier AU - Esperanza Agulló-Pascual AU - Eli Rothenberg AU - Mario Delmar AU - Hugues Abriel Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/07/10/674275.abstract N2 - Mutations in the gene encoding the sodium channel Nav1.5 cause various cardiac arrhythmias. This variety may arise from different determinants of Nav1.5 expression between cardiomyocyte domains. At the lateral membrane and T-tubules, Nav1.5 localization and function remain insufficiently characterized. We used novel single-molecule localization microscopy (SMLM) and modeling to define nanoscale features of Nav1.5 localization and distribution at the lateral membrane, groove, and T-tubules in wild-type, dystrophin-deficient (mdx) mice, and mice expressing C-terminally truncated Nav1.5 (ΔSIV). We show that Nav1.5 organizes as distinct clusters in the groove and T-tubules which density and distribution partially depend on SIV and dystrophin. We found that overall reduction in Nav1.5 expression in mdx and ΔSIV cells results in a non-uniform re-distribution with Nav1.5 being specifically reduced at the groove of ΔSIV and increased in T-tubules of mdx cardiomyocytes. Nav1.5 mutations may therefore site-specifically affect Nav1.5 localization and distribution depending on site-specific interacting proteins. ER -