O88454 (KCNK4_MOUSE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Potassium channel subfamily K member 4

Alternative name(s):
TWIK-related arachidonic acid-stimulated potassium channel protein
Short name=TRAAK

Gene names

Name:	Kcnk4
Synonyms:	Traak

Organism

Mus musculus (Mouse) [Reference proteome]

Taxonomic identifier

10090 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Mus › Mus

Protein attributes

Sequence length	398 AA.
Sequence status	Complete.
Protein existence	Evidence at transcript level

General annotation (Comments)

Function	Voltage insensitive, instantaneous, outwardly rectifying potassium channel. Outward rectification is reversed at high external K+ concentrations.
Subunit structure	Homodimer; disulfide-linked By similarity.
Subcellular location	Membrane; Multi-pass membrane protein Potential.
Tissue specificity	Expressed in brain, spinal cord and eye. Not detected in heart, skeletal muscle, liver, lungs, kidney and testis.
Miscellaneous	Activated by arachidonic acid and other unsaturated fatty acids. Not affected by volatile general anaesthetics such as chloroform, diethyl ether, halothane and isoflurane.
Sequence similarities	Belongs to the two pore domain potassium channel (TC 1.A.1.8) family. [View classification]

Ontologies

Keywords
Biological process	Ion transport Potassium transport Transport
Cellular component	Membrane
Coding sequence diversity	Alternative splicing
Domain	Transmembrane Transmembrane helix
Ligand	Potassium
Molecular function	Ion channel Potassium channel Voltage-gated channel
PTM	Disulfide bond Glycoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	potassium channel activity Inferred from electronic annotation. Source: UniProtKB-KW voltage-gated ion channel activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: O88454-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: O88454-2)

Also known as: TRAAKT; Truncated;

The sequence of this isoform differs from the canonical sequence as follows:
     63-67: KLLVE → KAMAI
     68-398: Missing.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 398	398	Potassium channel subfamily K member 4		PRO_0000101748
Regions
	Topological domain	1 – 3	3	Cytoplasmic Potential
	Transmembrane	4 – 24	21	Helical; Potential
	Intramembrane	89 – 113	25	Pore-forming; Name=Pore-forming 1; Potential
	Transmembrane	119 – 139	21	Helical; Potential
	Topological domain	140 – 171	32	Cytoplasmic Potential
	Transmembrane	172 – 192	21	Helical; Potential
	Intramembrane	198 – 222	25	Pore-forming; Name=Pore-forming 2; Potential
	Transmembrane	235 – 255	21	Helical; Potential
	Topological domain	256 – 398	143	Cytoplasmic Potential
Amino acid modifications
	Glycosylation	81	1	N-linked (GlcNAc...) Potential
	Glycosylation	84	1	N-linked (GlcNAc...) Potential
	Disulfide bond	52		Interchain By similarity
Natural variations
	Alternative sequence	63 – 67	5	KLLVE → KAMAI in isoform 2.		VSP_006690
	Alternative sequence	68 – 398	331	Missing in isoform 2.		VSP_006691

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified November 1, 1998. Version 1. Checksum: 478A834B7B7AEC92	FASTA	398	43,052
	10 20 30 40 50 60 MRSTTLLALL ALVLLYLVSG ALVFQALEQP HEQQAQKKMD HGRDQFLRDH PCVSQKSLED 70 80 90 100 110 120 FIKLLVEALG GGANPETSWT NSSNHSSAWN LGSAFFFSGT IITTIGYGNI VLHTDAGRLF 130 140 150 160 170 180 CIFYALVGIP LFGMLLAGVG DRLGSSLRRG IGHIEAIFLK WHVPPGLVRS LSAVLFLLIG 190 200 210 220 230 240 CLLFVLTPTF VFSYMESWSK LEAIYFVIVT LTTVGFGDYV PGDGTGQNSP AYQPLVWFWI 250 260 270 280 290 300 LFGLAYFASV LTTIGNWLRA VSRRTRAEMG GLTAQAASWT GTVTARVTQR TGPSAPPPEK 310 320 330 340 350 360 EQPLLPSSLP APPAVVEPAG RPGSPAPAEK VETPSPPTAS ALDYPSENLA FIDESSDTQS 370 380 390 ERGCALPRAP RGRRRPNPSK KPSRPRGPGR LRDKAVPV
	Isoform 2 (TRAAKT) (Truncated) [UniParc]. Checksum: 797A27D595231704	FASTA	67	7,594
	10 20 30 40 50 60 MRSTTLLALL ALVLLYLVSG ALVFQALEQP HEQQAQKKMD HGRDQFLRDH PCVSQKSLED FIKAMAI

References

[1]	"A neuronal two P domain K+ channel stimulated by arachidonic acid and polyunsaturated fatty acids." Fink M., Lesage F., Duprat F., Heurteaux C., Reyes R., Fosset M., Lazdunski M. EMBO J. 17:3297-3308(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Brain.
[2]	"Inhalational anesthetics activate two-pore-domain background K+ channels." Patel A.J., Honore E., Lesage F., Fink M., Romey G., Lazdunski M. Nat. Neurosci. 2:422-426(1999) [PubMed] [Europe PMC] [Abstract] Cited for: ACTIVATION.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF056492 mRNA. Translation: AAC40181.1.
IPI	IPI00229681. IPI00319653.
RefSeq	NP_032457.1. NM_008431.2.
UniGene	Mm.12894.
3D structure databases
ProteinModelPortal	O88454.
SMR	O88454. Positions 1-265.
ModBase	Search...
Protein-protein interaction databases
STRING	10090.ENSMUSP00000025908.
Protein family/group databases
TCDB	1.A.1.9.3. voltage-gated ion channel (VIC) superfamily.
PTM databases
PhosphoSite	O88454.
Proteomic databases
PRIDE	O88454.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENSMUST00000025908; ENSMUSP00000025908; ENSMUSG00000024957.
GeneID	16528.
KEGG	mmu:16528.
Organism-specific databases
CTD	50801.
MGI	MGI:1298234. Kcnk4.
Phylogenomic databases
eggNOG	NOG280717.
HOGENOM	HOG000013106.
HOVERGEN	HBG052234.
InParanoid	O88454.
KO	K04915.
OMA	QSERGCA.
OrthoDB	EOG42JNS5.
Gene expression databases
ArrayExpress	O88454.
Bgee	O88454.
CleanEx	MM_KCNK4.
Genevestigator	O88454.
GermOnline	ENSMUSG00000024957. Mus musculus.
Family and domain databases
InterPro	IPR003280. 2pore_dom_K_chnl. IPR008074. 2pore_dom_K_chnl_TRAAK. IPR013099. Ion_trans_2. [Graphical view]
Pfam	PF07885. Ion_trans_2. 2 hits. [Graphical view]
PRINTS	PR01333. 2POREKCHANEL. PR01691. TRAAKCHANNEL.
ProtoNet	Search...
Other
NextBio	289931.
SOURCE	Search...

Entry information

Entry name

KCNK4_MOUSE

Accession

Primary (citable) accession number: O88454

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 21, 2001
Last sequence update:	November 1, 1998
Last modified:	April 3, 2013
This is version 100 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program