Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the A-type potassium current class, the members of which may be important in the regulation of the fast repolarizing phase of action potentials in heart and thus may influence the duration of cardiac action potential.[provided by RefSeq, Mar 2011]
Forensic Context
A study in mice demonstrated that the KCNA4 was upregulated in the hearts of cardiomyocyte-specific Mbnl1/Mbnl2 double knockout animals, which recapitulated myotonic dystrophy cardiac pathology and sudden death [Lee et al. DOI:10.1093/hmg/ddac108]. This upregulation was identified through RNA sequencing analysis as part of a broader gene expression signature associated with arrhythmia and dilated cardiomyopathy.