KCNH2

This gene encodes a voltage-activated potassium channel belonging to the eag family. It shares sequence similarity with the Drosophila ether-a-go-go (eag) gene. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified.

Full Name

Potassium Voltage-Gated Channel Subfamily H Member 2

Function

Pore-forming (alpha) subunit of voltage-gated inwardly rectifying potassium channel. Channel properties are modulated by cAMP and subunit assembly. Mediates the rapidly activating component of the delayed rectifying potassium current in heart (IKr) (PubMed:18559421, PubMed:26363003, PubMed:27916661).
Isoform A-USO
Has no channel activity by itself, but modulates channel characteristics by forming heterotetramers with other isoforms which are retained intracellularly and undergo ubiquitin-dependent degradation.
Isoform B-USO
Has no channel activity by itself, but modulates channel characteristics by forming heterotetramers with other isoforms which are retained intracellularly and undergo ubiquitin-dependent degradation.

Biological Process

Cardiac muscle contractionManual Assertion Based On ExperimentIMP:BHF-UCL
Cellular response to xenobiotic stimulusManual Assertion Based On ExperimentIDA:BHF-UCL
Membrane depolarization during action potentialManual Assertion Based On ExperimentIDA:BHF-UCL
Membrane repolarizationManual Assertion Based On ExperimentIMP:UniProtKB
Membrane repolarization during action potentialManual Assertion Based On ExperimentIDA:BHF-UCL
Membrane repolarization during cardiac muscle cell action potentialManual Assertion Based On ExperimentIMP:BHF-UCL
Membrane repolarization during ventricular cardiac muscle cell action potentialManual Assertion Based On ExperimentIMP:BHF-UCL
Negative regulation of potassium ion export across plasma membraneManual Assertion Based On ExperimentIDA:BHF-UCL
Negative regulation of potassium ion transmembrane transportManual Assertion Based On ExperimentIDA:BHF-UCL
Positive regulation of potassium ion transmembrane transportManual Assertion Based On ExperimentIDA:BHF-UCL
Positive regulation of transcription, DNA-templatedManual Assertion Based On ExperimentIMP:ARUK-UCL
Potassium ion export across plasma membraneManual Assertion Based On ExperimentIDA:BHF-UCL
Potassium ion homeostasisManual Assertion Based On ExperimentIDA:BHF-UCL
Potassium ion import across plasma membraneManual Assertion Based On ExperimentIDA:BHF-UCL
Potassium ion transmembrane transportManual Assertion Based On ExperimentIDA:BHF-UCL
Regulation of heart rate by cardiac conductionManual Assertion Based On ExperimentIMP:BHF-UCL
Regulation of heart rate by hormoneManual Assertion Based On ExperimentTAS:BHF-UCL
Regulation of membrane potentialManual Assertion Based On ExperimentIDA:BHF-UCL
Regulation of membrane repolarizationManual Assertion Based On ExperimentIDA:BHF-UCL
Regulation of potassium ion transmembrane transportManual Assertion Based On ExperimentIDA:BHF-UCL
Regulation of ventricular cardiac muscle cell membrane repolarizationManual Assertion Based On ExperimentIMP:BHF-UCL
Ventricular cardiac muscle cell action potentialManual Assertion Based On ExperimentIMP:BHF-UCL

Cellular Location

Cell membrane

Involvement in disease

Long QT syndrome 2 (LQT2):
A heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. Deafness is often associated with long QT syndrome type 2.
Short QT syndrome 1 (SQT1):
A heart disorder characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. It causes syncope and sudden death.

Topology

Cytoplasmic: 1-403
Helical: 404-424
Extracellular: 425-450
Helical: 451-471
Cytoplasmic: 472-495
Helical: 496-516
Extracellular: 517-520
Helical: 521-541
Cytoplasmic: 542-547
Helical: 548-568
Extracellular: 569-611
Pore-forming: 612-632
Extracellular: 633-638
Helical: 639-659
Cytoplasmic: 660-1159

PTM

Phosphorylated on serine and threonine residues. Phosphorylation by PKA inhibits ion conduction.