SCN1B

Voltage-gated sodium channels are heteromeric proteins that function in the generation and propagation of action potentials in muscle and neuronal cells. They are composed of one alpha and two beta subunits, where the alpha subunit provides channel activity and the beta-1 subunit modulates the kinetics of channel inactivation. This gene encodes a sodium channel beta-1 subunit. Mutations in this gene result in generalized epilepsy with febrile seizures plus, Brugada syndrome 5, and defects in cardiac conduction. Multiple transcript variants encoding different isoforms have been found for this gene.

Full Name

Sodium Voltage-Gated Channel Beta Subunit 1

Function

Regulatory subunit of multiple voltage-gated sodium channel complexes that play important roles in excitable membranes in brain, heart and skeletal muscle. Enhances the presence of the pore-forming alpha subunit at the cell surface and modulates channel gating characteristics and the rate of channel inactivation. Modulates the activity of multiple pore-forming alpha subunits, such as SCN1A, SCN2A, SCN3A, SCN4A, SCN5A and SCN10A.
Isoform 2
Cell adhesion molecule that plays a critical role in neuronal migration and pathfinding during brain development. Stimulates neurite outgrowth (PubMed:21994374).
Has no regulatory function on the SCN2A sodium channel complex (PubMed:14622265).

Biological Process

Biological Process axon guidanceISS:BHF-UCL
Biological Process cardiac conductionISS:BHF-UCL
Biological Process cardiac muscle cell action potential involved in contractionManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process cardiac muscle contractionManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process cell adhesionIEA:UniProtKB-KW
Biological Process corticospinal neuron axon guidanceISS:BHF-UCL
Biological Process locomotionISS:BHF-UCL
Biological Process membrane depolarizationManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process membrane depolarization during cardiac muscle cell action potentialBy SimilarityISS:BHF-UCL
Biological Process membrane depolarization during Purkinje myocyte cell action potentialManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process neuronal action potential propagationISS:BHF-UCL
Biological Process positive regulation of neuron projection developmentISS:BHF-UCL
Biological Process positive regulation of sodium ion transportManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process regulation of atrial cardiac muscle cell membrane depolarizationManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process regulation of heart rate by cardiac conductionManual Assertion Based On ExperimentIMP:BHF-UCL
Biological Process regulation of sodium ion transmembrane transporter activityManual Assertion Based On ExperimentIDA:BHF-UCL
Biological Process regulation of ventricular cardiac muscle cell membrane repolarizationBy SimilarityISS:BHF-UCL
Biological Process sodium ion transmembrane transportManual Assertion Based On ExperimentIDA:BHF-UCL

Cellular Location

Isoform 1
Cell membrane
Perikaryon
Cell projection
Cell projection, axon
Detected at nodes of Ranvier on the sciatic nerve.
Isoform 2
Perikaryon
Cell projection
Secreted
Detected on Purkinje cells and their cell projections and on neuronal cell projections.

Involvement in disease

Generalized epilepsy with febrile seizures plus 1 (GEFS+1):
A rare autosomal dominant, familial condition with incomplete penetrance and large intrafamilial variability. Patients display febrile seizures persisting sometimes beyond the age of 6 years and/or a variety of afebrile seizure types. This disease combines febrile seizures, generalized seizures often precipitated by fever at age 6 years or more, and partial seizures, with a variable degree of severity.
Brugada syndrome 5 (BRGDA5):
A tachyarrhythmia characterized by right bundle branch block and ST segment elevation on an electrocardiogram (ECG). It can cause the ventricles to beat so fast that the blood is prevented from circulating efficiently in the body. When this situation occurs, the individual will faint and may die in a few minutes if the heart is not reset.
Atrial fibrillation, familial, 13 (ATFB13):
A familial form of atrial fibrillation, a common sustained cardiac rhythm disturbance. Atrial fibrillation is characterized by disorganized atrial electrical activity and ineffective atrial contraction promoting blood stasis in the atria and reduces ventricular filling. It can result in palpitations, syncope, thromboembolic stroke, and congestive heart failure.
Developmental and epileptic encephalopathy 52 (DEE52):
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE52 inheritance is autosomal recessive.

Topology

Extracellular: 19-160
Helical: 161-182
Cytoplasmic: 183-218