KCNK1 Ion channel that contributes to passive transmembrane potassium transport and to the regulation of the resting membrane potential in brain astrocytes, but also in kidney and in other tissues. Forms dimeric channels through which potassium ions pass in accordance with their electrochemical gradient. The channel is selective for K(+) ions at physiological potassium concentrations and at neutral pH, but becomes permeable to Na(+) at subphysiological K(+) levels and upon acidification of the extracellular medium. The homodimer has very low potassium channel activity, when expressed in heterologous systems, and can function as weakly inward rectifying potassium channel. Channel activity is modulated by activation of serotonin receptors. Heterodimeric channels containing KCNK1 and KCNK2 have much higher activity, and may represent the predominant form in astrocytes. Heterodimeric channels containing KCNK1 and KCNK3 or KCNK9 have much higher activity. Heterodimeric channels formed by KCNK1 and KCNK9 may contribute to halothane-sensitive currents. Mediates outward rectifying potassium currents in dentate gyrus granule cells and contributes to the regulation of their resting membrane potential. Contributes to the regulation of action potential firing in dentate gyrus granule cells and down-regulates their intrinsic excitability. In astrocytes, the heterodimer formed by KCNK1 and KCNK2 is required for rapid glutamate release in response to activation of G-protein coupled receptors, such as F2R and CNR1. Required for normal ion and water transport in the kidney. Contributes to the regulation of the resting membrane potential of pancreatic beta cells. The low channel activity of homodimeric KCNK1 may be due to sumoylation. The low channel activity may be due to rapid internalization from the cell membrane and retention in recycling endosomes. Belongs to the two pore domain potassium channel (TC 1.A.1.8) family. Detected in bronchial epithelial cells (PubMed:21964404). Detected in heart left atrium and left ventricle (PubMed:17478540). Detected in cardiac myocytes (at protein level) (PubMed:21653227). Widely expressed with high levels in heart, brain and kidney, and lower levels in colon, ovary, placenta, lung and liver (PubMed:8605869, PubMed:9362344). Highly expressed in cerebellum, and detected at lower levels in amygdala, caudate nucleus, brain cortex, hippocampus, putamen, substantia nigra, thalamus, dorsal root ganglion, spinal cord, pituitary, heart, kidney, lung, placenta, pancreas, stomach, small intestine, uterus and prostate (PubMed:11165377). Detected in right and left heart ventricle and atrium, and in heart Purkinje fibers (PubMed:17478540). Detected in bronchial epithelial cells (PubMed:21964404). Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral; Membrane protein, multi-pass
Chromosomal Location of Human Ortholog: 1q42.2
Cellular Component:  apical plasma membrane; brush border membrane; cell junction; dendrite; integral component of membrane; integral component of plasma membrane; intracellular membrane-bounded organelle; inward rectifier potassium channel complex; perikaryon; plasma membrane; potassium channel complex; recycling endosome; synapse; voltage-gated potassium channel complex
Molecular Function:  identical protein binding; inward rectifier potassium channel activity; potassium channel activity; potassium ion leak channel activity; protein binding; sodium channel activity
Biological Process:  cardiac conduction; potassium ion transmembrane transport; potassium ion transport; regulation of resting membrane potential; response to nicotine; sodium ion transmembrane transport
Reference #:  O00180 (UniProtKB)
Alt. Names/Synonyms: DPK; HOHO; HOHO1; Inward rectifying potassium channel protein TWIK-1; K2P1; K2p1.1; KCNK1; KCNO1; Potassium channel K2P1; Potassium channel KCNO1; Potassium channel subfamily K member 1; potassium channel, subfamily K, member 1; potassium channel, two pore domain subfamily K, member 1; potassium inwardly-rectifying channel, subfamily K, member 1; potassium two pore domain channel subfamily K member 1; tandem of P domains in a weak inward rectifying K+ channel 1; TWIK-1; TWIK1
Gene Symbols: KCNK1
Molecular weight: 38,143 Da
Basal Isoelectric point: 5.94  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  STRING  |  cBioPortal  |  Wikipedia  |  Reactome  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene