InterPro : IPR005399

Name  Potassium channel, voltage-dependent, beta subunit, KCNAB-related Short Name  K_chnl_volt-dep_bsu_KCNAB-rel
Type  Family Description  This entry consists of the voltage-dependent potassium channel beta subunit KCNAB and related proteins. The bacterial proteins in this entry lack apparent alpha subunit partners and predicted to function as soluble aldo/keto reductase enzymes [, ].Potassium channels are the most diverse group of the ion channel family[, ]. They are important in shaping the action potential, and in neuronal excitability and plasticity []. The potassium channel family iscomposed of several functionally distinct isoforms, which can be broadlyseparated into 2 groups []: the practically non-inactivating 'delayed' group and the rapidly inactivating 'transient' group.These are all highly similar proteins, with only small amino acidchanges causing the diversity of the voltage-dependent gating mechanism,channel conductance and toxin binding properties. Each type of K+channel is activated by different signals and conditions depending on their type of regulation: some open in response to depolarisation of the plasma membrane; others in response to hyperpolarisation or an increase in intracellular calcium concentration; some can be regulated by binding of a transmitter, together with intracellular kinases; while others are regulated by GTP-binding proteins orother second messengers []. In eukaryotic cells, K+channelsare involved in neural signalling and generation of the cardiac rhythm, act as effectors in signal transduction pathways involving G protein-coupled receptors (GPCRs) and may have a role in target cell lysis by cytotoxic T-lymphocytes []. In prokaryotic cells, they play a role in themaintenance of ionic homeostasis [].All K+channels discovered so far possess a core of alpha subunits, each comprising either one or two copies of a highly conserved pore loop domain (P-domain). The P-domain contains the sequence (T/SxxTxGxG), which hasbeen termed the K+selectivity sequence.In families that contain one P-domain, four subunits assemble to form a selective pathway for K+across the membrane.However, it remains unclear how the 2 P-domain subunits assemble to form a selective pore. The functional diversity of these families can arise through homo- or hetero-associations of alpha subunits or association with auxiliary cytoplasmic beta subunits. K+channel subunits containing one pore domain can be assigned into one of two superfamilies: those that possess six transmembrane (TM) domains and those that possess only two TM domains.The six TM domain superfamily can be further subdivided into conserved gene families: the voltage-gated (Kv) channels; the KCNQ channels (originally known as KvLQT channels); the EAG-like K+channels; and three types of calcium (Ca)-activated K+channels (BK, IK and SK)[]. The 2TM domain family comprises inward-rectifying K+channels. In addition, there are K+channel alpha-subunits that possess two P-domains. These are usually highly regulated K+selective leak channels.The KCNAB family (also known as the Kvbeta family) of voltage-dependent potassium channel beta subunits form complexes with the alpha subunits which can modify the properties of the channel. Four of these soluble beta subunits form a complex with four alpha subunit cytoplasmic (T1) regions. These subunits belong to the family of are NADPH-dependent aldo-keto reductases, and bind NADPH-cofactors in their active sites. Changes in the oxidoreductase activity appear to markedly influence the gating mode of Kv channels, since mutations to the catalytic residues in the active site lessen the inactivating activity of KCNAB []. The KCNAB family is further divided into 3 subfamilies: KCNAB1 (Kvbeta1), KCNAB2 (Kvbeta2) and KCNAB3 (Kvbeta3).

Sequence Features

GO Displayer


InterPro protein domain ID --> Contigs



1 Child Features

Id Name Short Name Type
IPR005983 Potassium channel, voltage-dependent, beta subunit, KCNAB K_chnl_volt-dep_bsu_KCNAB Family

0 Contains

0 Found In

1 Parent Features

Id Name Short Name Type
IPR001395 Aldo/keto reductase Aldo/ket_red Family

10 Publications

First Author Title Year Journal Volume Pages
Perney TM The molecular biology of K+ channels. 1991 Curr Opin Cell Biol 3 663-70
Luneau C Shaw-like rat brain potassium channel cDNA's with divergent 3' ends. 1991 FEBS Lett 288 163-7
Attali B Cloning, functional expression, and regulation of two K+ channels in human T lymphocytes. 1992 J Biol Chem 267 8650-7
Schwarz TL Multiple potassium-channel components are produced by alternative splicing at the Shaker locus in Drosophila. 1988 Nature 331 137-42
Tempel BL Cloning of a probable potassium channel gene from mouse brain. 1988 Nature 332 837-9
Stühmer W Molecular basis of functional diversity of voltage-gated potassium channels in mammalian brain. 1989 EMBO J 8 3235-44
Miller C An overview of the potassium channel family. 2000 Genome Biol 1 REVIEWS0004
Bähring R Coupling of voltage-dependent potassium channel inactivation and oxidoreductase active site of Kvbeta subunits. 2001 J Biol Chem 276 22923-9
Grant AW A novel aldo-keto reductase from Escherichia coli can increase resistance to methylglyoxal toxicity. 2003 FEMS Microbiol Lett 218 93-9
Desai KK A metabolic bypass of the triosephosphate isomerase reaction. 2008 Biochemistry 47 7983-5

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Rozanski, A., Moon, H., Brandl, H., Martín-Durán, J. M., Grohme, M., Hüttner, K., Bartscherer, K., Henry, I., & Rink, J. C.
PlanMine 3.0—improvements to a mineable resource of flatworm biology and biodiversity
Nucleic Acids Research, gky1070. doi:10.1093/nar/gky1070 (2018)