KV1.5 | Shaker Related Potassium Channel Member 5

K_V1.5 belongs to the delayed rectifier class. It can form functional homotetrameric channels and heterotetrameric channels that contain variable proportions of KCNA1, KCNA2, KCNA4, KCNA5, and possibly other family members as well. Channel properties are modulated by cytoplasmic beta subunits that regulate the subcellular location of the alpha subunits and promote rapid inactivation. Homotetrameric channels display rapid activation and slow inactivation. The function of K_V1.5 restores the resting membrane potential of beta cells after depolarization and thereby contributes to the regulation of insulin secretion. Expressed in atrial myocytes K_V1.5 forms the I_Kur current. It is also expressed in the human ventricle where it is possible that it contributes to the K⁺ current through formation of heteromultimeric Potassium channels with other K_V-alpha subunits.

Gene:
KCNA5

Human Protein:
UniProt P22460

Tissue:
Cardiac and smooth muscle, beta cells, colon, aorta, stomach and pulmonary artery, neurons, kidney

Function/ Application:
Excitability, repolarization cardiac action potential, insulin secretion, pulmonary vascular function, cardiac I_Kur current

Pathology:
Atrial fibrillation type 7, familial atrial fibrillation, insulinoma, sudden cardiac death, prolonged PR interval, palpitations, prolonged QTc interval, autosomal dominant inheritance

Interaction:
K_Vβ1, K_Vβ2, K_Vβ3.1, SAP97 , Src Tyrosine Kinase, caveolin 1, caveolin 3, α-actinin-1, α-actinin-2, DLG1, DLG4, CACNA1C

Modulator:
α-linolenic acid, TEA, 4-AP, nifedipine, flecainide, bupivacaine, E-4031, XE 991 dihydrochloride

Assays:
Patch Clamp: whole cell, temperature control

Recommended Reviews:
Gutman et al. (2005) International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels. Pharmacol Rev 57(4):473-508