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). Isoform 3 has no channel activity by itself, but modulates channel characteristics when associated with isoform 1.
Highly expressed in heart and brain.
Involvement in disease
Defects in KCNH2 are the cause of long QT syndrome type 2 (LQT2) [MIM:613688]. Long QT syndromes are heart disorders 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. Deafness is often associated with LQT2. Defects in KCNH2 are the cause of short QT syndrome type 1 (SQT1) [MIM:609620]. Short QT syndromes are heart disorders characterized by idiopathic persistently and uniformly short QT interval on ECG in the absence of structural heart disease in affected individuals. They cause syncope and sudden death.
Belongs to the potassium channel family. H (Eag) (TC 1.A.1.20) subfamily. Kv11.1/KCNH2 sub-subfamily. Contains 1 cyclic nucleotide-binding domain. Contains 1 PAC (PAS-associated C-terminal) domain. Contains 1 PAS (PER-ARNT-SIM) domain.
The segment S4 is probably the voltage-sensor and is characterized by a series of positively charged amino acids at every third position.
Phosphorylated on serine and threonine residues. Phosphorylation by PKA inhibits ion conduction.
Zeng W et al. Silencing of hERG1 Gene Inhibits Proliferation and Invasion, and Induces Apoptosis in Human Osteosarcoma Cells by Targeting the NF-?B Pathway. J Cancer7:746-57 (2016).
Read more (PubMed: 27076857) »