The adhesion function of the sodium channel beta subunit (β1) contributes to cardiac action potential propagation.

ABSTRACT: Computational modeling indicates that cardiac conduction may involve ephaptic coupling - intercellular communication involving electrochemical signaling across narrow extracellular clefts between cardiomyocytes. We hypothesized that β1(SCN1B) -mediated adhesion scaffolds trans-activating Na_V1.5 (SCN5A) channels within narrow (<30 nm) perinexal clefts adjacent to gap junctions (GJs), facilitating ephaptic coupling. Super-resolution imaging indicated preferential β1 localization at the perinexus, where it co-locates with Na_V1.5. Smart patch clamp (SPC) indicated greater sodium current density (I_Na) at perinexi, relative to non-junctional sites. A novel, rationally designed peptide, βadp1, potently and selectively inhibited β1-mediated adhesion, in elec

SUBMITTER: Veeraraghavan R 

PROVIDER: S-EPMC6122953 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature