Q63664 (IRK8_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
ATP-sensitive inward rectifier potassium channel 8

Alternative name(s):
Inward rectifier K(+) channel Kir6.1
Potassium channel, inwardly rectifying subfamily J member 8
uKATP-1

Gene names

Name:

Kcnj8

Organism

Rattus norvegicus (Rat) [Reference proteome]

Taxonomic identifier

10116 [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 › Rattus

Protein attributes

Sequence length	424 AA.
Sequence status	Complete.
Protein existence	Evidence at transcript level

General annotation (Comments)

Function	This potassium channel is controlled by G proteins. Inward rectifier potassium channels are characterized by a greater tendency to allow potassium to flow into the cell rather than out of it. Their voltage dependence is regulated by the concentration of extracellular potassium; as external potassium is raised, the voltage range of the channel opening shifts to more positive voltages. The inward rectification is mainly due to the blockage of outward current by internal magnesium. Can be blocked by external barium.
Subcellular location	Membrane; Multi-pass membrane protein.
Tissue specificity	Expressed ubiquitously, including pancreatic islets, pituitary, skeletal muscle and heart.
Sequence similarities	Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ8 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Potassium transport Transport
Cellular component	Membrane
Coding sequence diversity	Polymorphism
Domain	Transmembrane Transmembrane helix
Ligand	Potassium
Molecular function	Ion channel Voltage-gated channel
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	defense response to virus Inferred from electronic annotation. Source: Compara heart development Inferred from electronic annotation. Source: Compara kidney development Inferred from expression pattern PubMed 12466933. Source: RGD potassium ion import Inferred from direct assay Ref.1. Source: RGD response to exogenous dsRNA Inferred from electronic annotation. Source: Compara response to lipopolysaccharide Inferred from electronic annotation. Source: Compara response to pH Inferred from direct assay PubMed 12677015. Source: RGD vasodilation Inferred from direct assay PubMed 12677015. Source: RGD
Cellular_component	ATP-sensitive potassium channel complex Inferred from direct assay PubMed 17097686. Source: RGD mitochondrion Inferred from direct assay PubMed 15983113PubMed 16050978. Source: RGD myofibril Inferred from electronic annotation. Source: Compara sarcolemma Inferred from direct assay PubMed 15647111. Source: RGD
Molecular_function	ATP binding Inferred from direct assay PubMed 15775962. Source: RGD ATP-activated inward rectifier potassium channel activity Inferred from direct assay PubMed 17097686Ref.1. Source: RGD
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 424	424	ATP-sensitive inward rectifier potassium channel 8		PRO_0000154949
Regions
	Topological domain	1 – 69	69	Cytoplasmic By similarity
	Transmembrane	70 – 94	25	Helical; Name=M1; By similarity
	Topological domain	95 – 126	32	Extracellular By similarity
	Intramembrane	127 – 138	12	Helical; Pore-forming; Name=H5; By similarity
	Intramembrane	139 – 145	7	Pore-forming; By similarity
	Topological domain	146 – 154	9	Extracellular By similarity
	Transmembrane	155 – 176	22	Helical; Name=M2; By similarity
	Topological domain	177 – 424	248	Cytoplasmic By similarity
	Motif	140 – 145	6	Selectivity filter By similarity
Sites
	Site	170	1	Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesium By similarity
Natural variations
	Natural variant	23	1	R → H.
	Natural variant	48	1	K → Q.
	Natural variant	150	1	E → G.
	Natural variant	170	1	N → D.
	Natural variant	241	1	V → A.
	Natural variant	379	1	S → F.

Sequences

	Sequence		Length	Mass (Da)
	Q63664 [UniParc]. Last modified November 1, 1996. Version 1. Checksum: 22548313B92FE095	FASTA	424	47,963
	10 20 30 40 50 60 MLARKSIIPE EYVLARIAAE NLRKPRIRDR LPKARFIAKS GACNLAHKNI REQGRFLQDI 70 80 90 100 110 120 FTTLVDLKWR HTLVIFTMSF LCSWLLFAIM WWLVAFAHGD IYAYMEKGIT EKSGLESAVC 130 140 150 160 170 180 VTNVRSFTSA FLFSIEVQVT IGFGGRMMTE ECPLAITVLI LQNIVGLIIN AVMLGCIFMK 190 200 210 220 230 240 TAQAHRRAET LIFSRHAVIA VRNGKLCFMF RVGDLRKSMI ISASVRIQVV KKTTTPEGEV 250 260 270 280 290 300 VPIHQQDIPV DNPIESNNIF LVAPLIICHV IDKRSPLYDI SATDLVNQDL EVIVILEGVV 310 320 330 340 350 360 ETTGITTQAR TSYIAEEIQW GHRFVSIVTE EEGVYSVDYS KFGNTVRVAA PRCSARELDE 370 380 390 400 410 420 KPSILIQTLQ KSELSHQNSL RKRNSMRRNN SMRRSNSIRR NNSSLMVPKV QFMTPEGNQC PSES

References

[1]	"Cloning and functional characterization of a novel ATP-sensitive potassium channel ubiquitously expressed in rat tissues, including pancreatic islets, pituitary, skeletal muscle, and heart." Inagaki N., Tsuura Y., Namba N., Masuda K., Gonoi T., Horie M., Seino Y., Mizuta M., Seino S. J. Biol. Chem. 270:5691-5694(1995) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Sprague-Dawley. Tissue: Pancreatic islet.
[2]	Cao K., Wang R. Submitted (MAY-2000) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA], VARIANTS. Strain: Sprague-Dawley. Tissue: Vascular smooth muscle.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	D42145 mRNA. Translation: BAA07716.1. AB043636 mRNA. Translation: BAA96237.1. AB043637 mRNA. Translation: BAA96238.1.
IPI	IPI00211081.
PIR	I60373.
RefSeq	NP_058795.3. NM_017099.4.
UniGene	Rn.229203.
3D structure databases
ProteinModelPortal	Q63664.
SMR	Q63664. Positions 184-361.
ModBase	Search...
PTM databases
PhosphoSite	Q63664.
Proteomic databases
PaxDb	Q63664.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENSRNOT00000018057; ENSRNOP00000018057; ENSRNOG00000013463.
GeneID	25472.
KEGG	rno:25472.
UCSC	RGD:2960. rat.
Organism-specific databases
CTD	3764.
RGD	2960. Kcnj8.
Phylogenomic databases
eggNOG	NOG72812.
GeneTree	ENSGT00690000101708.
HOGENOM	HOG000237325.
HOVERGEN	HBG006178.
InParanoid	Q63664.
KO	K05001.
OMA	VIAVRNN.
OrthoDB	EOG4DFPNM.
Gene expression databases
Genevestigator	Q63664.
GermOnline	ENSRNOG00000013463. Rattus norvegicus.
Family and domain databases
Gene3D	2.60.40.1400. 1 hit.
InterPro	IPR014756. Ig_E-set. IPR016449. K_chnl_inward-rec_Kir. IPR003278. K_chnl_inward-rec_Kir6.1. IPR013518. K_chnl_inward-rec_Kir_cyto. [Graphical view]
PANTHER	PTHR11767. PTHR11767. 1 hit.
Pfam	PF01007. IRK. 1 hit. [Graphical view]
PIRSF	PIRSF005465. GIRK_kir. 1 hit.
PRINTS	PR01331. KIR61CHANNEL. PR01320. KIRCHANNEL.
SUPFAM	SSF81296. Ig_E-set. 1 hit.
ProtoNet	Search...
Other
BindingDB	Q63664.
ChEMBL	CHEMBL4293.
NextBio	606777.

Entry information

Entry name

IRK8_RAT

Accession

Primary (citable) accession number: Q63664
Secondary accession number(s): Q9JM49, Q9JM50

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1997
Last sequence update:	November 1, 1996
Last modified:	April 3, 2013
This is version 104 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program