Protein Domain : IPR020467

Type:  Family Name:  Potassium channel, voltage dependent, Kv1.4
Description:  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 broadly separated 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 acid changes 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 or other second messengers []. In eukaryotic cells, K+channels are 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 Kv family can be divided into several subfamilies on the basis of sequence similarity and function. Four of these subfamilies, Kv1 (Shaker), Kv2 (Shab), Kv3 (Shaw) and Kv4 (Shal), consist of pore-forming alpha subunits that associate with different types of beta subunit. Each alpha subunit comprises six hydrophobic TM domains with a P-domain between the fifth and sixth, which partially resides in the membrane. The fourth TM domain has positively charged residues at every third residue and acts as a voltage sensor, which triggers the conformational change that opens the channel pore in response to a displacement in membrane potential []. More recently, 4 new electrically-silent alpha subunits have been cloned: Kv5 (KCNF), Kv6 (KCNG), Kv8 and Kv9 (KCNS). These subunits do not themselves possess any functional activity, but appear to form heteromeric channels with Kv2 subunits, and thus modulate Shab channel activity []. When highly expressed, they inhibit channel activity, but at lower levels show more specific modulatory actions.The first Kv1 sequence (also known as Shaker) was found in Drosophila melanogaster(Fruit fly). Several vertebrate potassium channels with similar amino acid sequences were subsequently found and, together with the D. melanogaster Shaker channel, now constitute the Kv1 family. The family consists of at least 6 genes (Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5 and Kv1.6) which each play distinct physiological roles. A conserved motif found towards the C terminus of these channels is required for efficient processing and surface expression []. Variations in this motif account for the differences in cell surface expression and localisation between family members. These channels are mostly expressed in the brain, but can also be found in non-excitable cells, such as lymphocytes []. Kv1.4 channels are found in similar regions to Kv1.1 channels. They are particularly targeted to axons and possibly terminals, suggesting apre-synaptic role in synaptic transmission. Short Name:  K_chnl_volt-dep_Kv1.4
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0 Child Features

4 Contains

DB identifier Type Name
IPR011333 Domain POZ domain
IPR000210 Domain BTB/POZ domain
IPR003131 Domain Potassium channel tetramerisation-type BTB domain
IPR012897 Domain Potassium channel, voltage dependent, Kv1.4, tandem inactivation domain

1 Cross References

Identifier
PR01511

0 Found In

0 GO Annotation

0 Ontology Annotations

1 Parent Features

DB identifier Type Name
IPR003972 Family Potassium channel, voltage dependent, Kv1

10 Proteins

DB identifier UniProt Accession Secondary Identifier Organism Name Length
Cre15.g639552.t1.1 A0A2K3CWQ0 PAC:30783589 Chlamydomonas reinhardtii 237  
Eucgr.K01137.1.p A0A059A0U2 PAC:32068926 Eucalyptus grandis 94  
Pum0111s0035.1.p A0A1X6PC96 PAC:38007588 Porphyra umbilicalis 733  
Pum0535s0011.1.p A0A1X6NSS0 PAC:38010216 Porphyra umbilicalis 661  
Pum0025s0031.1.p A0A1X6PKB2 PAC:38018897 Porphyra umbilicalis 183  
Pum0171s0020.1.p A0A1X6P7K1 PAC:38012399 Porphyra umbilicalis 322  
Pum0305s0002.1.p A0A1X6P004 PAC:38008321 Porphyra umbilicalis 435  
Pum0497s0001.1.p A0A1X6NTD3 PAC:38013026 Porphyra umbilicalis 293  
Pum0058s0077.1.p A0A1X6PH30 PAC:38011085 Porphyra umbilicalis 428  
Vocar.0005s0353.1.p PAC:32884012 Volvox carteri 150  

11 Publications

First Author Title Year Journal Volume Pages PubMed ID
            1772658
            1879548
            1373731
            2448635
            2451788
            2555158
            11178249
            10798390
            9305895
            10712896
            11343973