SCN5A
This protein mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na(+) ions may pass in accordance with their electrochemical gradient. It is a tetrodotoxin-resistant Na(+) channel isoform. This channel is responsible for the initial upstroke of the action potential. Channel inactivation is regulated by intracellular calcium levels. Belongs to the sodium channel (TC 1.A.1.10) family. Nav1.5/SCN5A subfamily. Found in jejunal circular smooth muscle cells (at protein level). Expressed in human atrial and ventricular cardiac muscle but not in adult skeletal muscle, brain, myometrium, liver, or spleen. Isoform 4 is expressed in brain. 6 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Channel, sodium; Membrane protein, integral; Membrane protein, multi-pass
Molecular Function: ankyrin binding; calmodulin binding; enzyme binding; fibroblast growth factor binding; nitric-oxide synthase binding; protein binding; protein domain specific binding; protein kinase binding; scaffold protein binding; transmembrane transporter binding; ubiquitin protein ligase binding; voltage-gated monoatomic ion channel activity; voltage-gated sodium channel activity; voltage-gated sodium channel activity involved in AV node cell action potential; voltage-gated sodium channel activity involved in bundle of His cell action potential; voltage-gated sodium channel activity involved in cardiac muscle cell action potential; voltage-gated sodium channel activity involved in Purkinje myocyte action potential; voltage-gated sodium channel activity involved in SA node cell action potential
Biological Process: action potential; atrial cardiac muscle cell action potential; AV node cell action potential; AV node cell to bundle of His cell communication; brainstem development; bundle of His cell action potential; calcium ion homeostasis; cardiac muscle cell action potential involved in contraction; cardiac muscle contraction; cardiac ventricle development; cell communication involved in cardiac conduction; cellular response to calcium ion; cerebellum development; establishment of localization in cell; membrane depolarization; membrane depolarization during action potential; membrane depolarization during atrial cardiac muscle cell action potential; membrane depolarization during AV node cell action potential; membrane depolarization during bundle of His cell action potential; membrane depolarization during cardiac muscle cell action potential; membrane depolarization during Purkinje myocyte cell action potential; membrane depolarization during SA node cell action potential; muscle cell cellular homeostasis; neuronal action potential; odontogenesis of dentin-containing tooth; positive regulation of action potential; positive regulation of epithelial cell proliferation; positive regulation of heart rate; positive regulation of sodium ion transport; regulation of atrial cardiac muscle cell membrane depolarization; regulation of atrial cardiac muscle cell membrane repolarization; regulation of cardiac muscle cell contraction; regulation of heart rate; regulation of heart rate by cardiac conduction; regulation of monoatomic ion transmembrane transport; regulation of sodium ion transmembrane transport; regulation of ventricular cardiac muscle cell membrane depolarization; regulation of ventricular cardiac muscle cell membrane repolarization; response to denervation involved in regulation of muscle adaptation; response to organic cyclic compound; SA node cell action potential; sodium ion import across plasma membrane; sodium ion transmembrane transport; sodium ion transport; telencephalon development; ventricular cardiac muscle cell action potential