Reaction: AKAP9:KCNQ1 tetramer:KCNE dimer transports K+ from cytosol to extracellular region
- in pathway: Phase 3 - rapid repolarisation
Two potassium currents, IKs and IKr, provide the principal repolarising currents in cardiac myocytes for the termination of action potentials. Potassium voltage-gated channel subfamily KQT member 1 (KCNQ1 aka Kv7.1) is the pore-forming alpha subunit of a complex also containing an ancillary protein from potassium voltage-gated channel subfamily E members (KCNE) that assemble as a beta subunit. The stoichiometry is believed to be 4 KCNQ1 subunits to 2 KCNE subunits (Plant et al. 2014). A-kinase anchor protein 9 (AKAP9) is an essential anchoring protein that binds to KCNQ1. Defects in KCNQ1 that disrupt this binding can result in type 1 long-QT syndrome (LQT1), a hereditary, potentially lethal arrhythmia syndrome (Chen et al. 2007). The AKAP9:KCNQ1:KCNE complex creates the slowly activating delayed rectifier cardiac potassium current IKs by the efflux of K+ from cardiac cells (Schroeder et al. 2000).
Reaction - small molecule participants:
K+ [extracellular region]
K+ [cytosol]
K+ [extracellular region]
K+ [cytosol]
Reactome.org reaction link: R-HSA-5577050
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Reaction input - small molecules:
potassium(1+)
potassium(1+)
Reaction output - small molecules:
potassium(1+)
potassium(1+)
Reactome.org link: R-HSA-5577050