NaV1.4 | sodium voltage-gated channel alpha subunit 4
Family:
Sodium channels
Subgroups:
NaV1.1-1.9
Topology:
Alpha subunits consist of four homologous domains (I-IV) with six transmembrane alpha helices (S1–S6) and a pore-forming loop. One a subunit may associate with 1 or 2 b subunits to make up the channel.
NaV1.4: Background Information
NaV1.4 is expressed in skeletal muscle, and mutations in this gene have been linked to several myotonia and periodic paralysis disorders. For the body to move normally, skeletal muscles must tense (contract) and relax in a coordinated way. One of the changes that helps trigger muscle contractions is the flow of positively charged ions, including sodium, into muscle cells. NaV1.4 ion channel controls the flow of sodium ions into these cells. NaV1.4 is TTX-sensitive.
Gene:
SCN4A
Human Protein:
UniProt P35499
Tissue:
Skeletal muslce
Function/ Application:
Generation and propagation of action potentials in muscle
Pathology:
Myotonia (PMC, PAM), periodic paralysis (HyperPP, HypoPP), congenital myasthenic syndrome
Interaction:
β1 subunit, syntrophin, calmodulin, DISC
Modulator:
Tetrodotoxin, saxitoxin, veratridine, grayanotoxin, AFT-II, Lidocaine
Assays:
Patch Clamp: whole cell, room temperature, State- and use-dependence
Particularities:
NaV channel analysis requires GigaOhm seals and a stable and low access resistance
Recommended Reviews:
International Union of Pharmacology. XLVII. Nomenclature and Structure-Function Relationships of Voltage-Gated Sodium Channels. Pharmacol Rev 57: 397–409, Catterall, et al. 2005