Protein Domain : IPR003092

Type:  Family Name:  Two pore domain potassium channel, TASK family
Description:  2P-domain channels influence the resting membrane potential and as a result can control cell excitability. In addition, they pass K+ in response to changes in membrane potential, and are also tightly regulated by molecular oxygen, GABA (gamma-aminobutyric acid), noradrenaline and serotonin.The first member of this family (TOK1), cloned from Saccharomyces cerevisiae[], ispredicted to have eight potential transmembrane (TM) helices. However, subsequently-cloned two P-domain family members from Drosophila andmammalian species are predicted to have only four TM segments. They are usually referred to as TWIK-related channels (Tandem of P-domains in a Weakly Inward rectifying K+ channel) [, , , ]. Functional characterisation of these channels has revealed a diversity of properties in that they may show inward or outward rectification, their activity may be modulated in different directions by protein phosphorylation, and their sensitivity to changes in intracellular or extracellular pH varies. Despite these disparate properties, they are all thought to share the same topology offour TM segments, including two P-domains. That TWIK-related K+ channels all produce instantaneous and non-inactivating K+ currents, which do notdisplay a voltage-dependent activation threshold, suggests that they are background (leak) K+ channels involved in the generation and modulation of the resting membrane potential in various cell types. Further studies have revealed that they may be found in many species, including: plants, invertebrates and mammals.TASK is a member of the TWIK-related (two P-domain) K+channel family identified in human tissues []. It is widely distributed, being particularly abundant in the pancreas and placenta, but it is also found inthe brain, heart, lung and kidney. Its amino acid identity to TWIK-1 and TREK-1 is rather low, being about 25-28%. However, it is thought to share the same topology of four TM segments, with two P-domains. TASK is very sensitive to variations in extracellular pH in the physiological range, changing from fully-open to closed in approximately 0.5 pH units around pH 7.4. Thus, it may well be a biological sensor of external pH variations. Short Name:  2pore_dom_K_chnl_TASK

3 Child Features

DB identifier Type Name
IPR005406 Family Potassium channel subfamily K member 3
IPR005407 Family Potassium channel subfamily K member 9
IPR008073 Family Potassium channel subfamily K member 15

1 Contains

DB identifier Type Name
IPR013099 Domain Potassium channel domain

2 Cross Referencess

Identifier
PIRSF038061
PR01095

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0005267 IPR003092
GO:0071805 IPR003092
GO:0016020 IPR003092

3 Ontology Annotations

GO Term Gene Name
GO:0005267 IPR003092
GO:0071805 IPR003092
GO:0016020 IPR003092

1 Parent Features

DB identifier Type Name
IPR003280 Family Two pore domain potassium channel

0 Proteins

5 Publications

First Author Title Year Journal Volume Pages PubMed ID
            8605869
            9003761
            9312005
            7651518
            8917578