Enables scaffold protein binding activity and voltage-gated sodium channel activity involved in SA node cell action potential. Acts upstream of or within several processes, including cardiac muscle cell action potential involved in contraction; regulation of heart contraction; and sodium ion import across plasma membrane. Located in several cellular components, including T-tubule; intercalated disc; and lateral plasma membrane. Part of sodium channel complex. Is expressed in several structures, including cranial ganglion; epidermis; heart; sensory organ; and skeleton. Used to study Brugada syndrome 1; dilated cardiomyopathy 1E; long QT syndrome 3; progressive familial heart block type IA; and sick sinus syndrome. Human ortholog(s) of this gene implicated in heart conduction disease (multiple); intrinsic cardiomyopathy (multiple); and sudden infant death syndrome. Orthologous to human SCN5A (sodium voltage-gated channel alpha subunit 5). [provided by Alliance of Genome Resources, Apr 2022]