KV1.5 | Shaker Related Potassium Channel Member 5
Family:
Potassium channels
Subgroups:
Shaker (KV1.1–KV1.8), Shab (KV2.1-KV2.2), Shaw (KV3.1–KV3.4), Shal (KV4.1–KV4.3), KQT like (KV7.1–KV7.5), Eag related (KV10.1-KV10.2), Erg related (KV11.1–KV11.3), Elk related (KV12.1)
Topology:
Contains six transmembrane domains (S1–S6), four single subunits form a pore, homotetramers and heterotetramers are possible.
KV1.5 Background Information
KV1.5 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 KV1.5 restores the resting membrane potential of beta cells after depolarization and thereby contributes to the regulation of insulin secretion. Expressed in atrial myocytes KV1.5 forms the IKur 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 KV-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 IKur current
Pathology:
Atrial fibrillation type 7, familial atrial fibrillation, insulinoma, sudden cardiac death, prolonged PR interval, palpitations, prolonged QTc interval, autosomal dominant inheritance
Interaction:
KVβ1, KVβ2, KVβ3.1, 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