P52188 (IRK12_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
ATP-sensitive inward rectifier potassium channel 12

Alternative name(s):
Inward rectifier K(+) channel Kir2.2
Short name=IRK-2
Potassium channel, inwardly rectifying subfamily J member 12

Gene names

Name:	Kcnj12
Synonyms:	Irk2

Organism

Rattus norvegicus (Rat)

Taxonomic identifier

10116 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Rattus

Protein attributes

Sequence length	427 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Probably participates in establishing action potential waveform and excitability of neuronal and muscle tissues. 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 extracellular barium and cesium. Ref.2
Subunit structure	Association, via its PDZ-recognition domain, with LIN7A, LIN7B, LIN7C, DLG1, CASK and APBA1 plays a key role in its localization and trafficking.
Subcellular location	Membrane; Multi-pass membrane protein.
Tissue specificity	Highest level in cerebellum. Moderately found in kidney, forebrain and skeletal muscle. Not detected in uterus, liver and pancreas.
Sequence similarities	Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ12 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Potassium transport Transport
Cellular component	Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Potassium
Molecular function	Ionic channel Voltage-gated channel
PTM	Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Cellular component	T-tubule Inferred from direct assay. Source: RGD dendrite Inferred from direct assay. Source: RGD integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW neuronal cell body Inferred from direct assay. Source: RGD
Molecular function	PDZ domain binding Inferred from physical interaction. Source: RGD inward rectifier potassium channel activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 427	427	ATP-sensitive inward rectifier potassium channel 12		PRO_0000154964
Regions
	Topological domain	1 – 80	80	Cytoplasmic By similarity
	Transmembrane	81 – 105	25	Helical; Name=M1; By similarity
	Topological domain	106 – 129	24	Extracellular By similarity
	Intramembrane	130 – 141	12	Helical; Pore-forming; Name=H5; By similarity
	Intramembrane	142 – 148	7	Pore-forming; By similarity
	Topological domain	149 – 157	9	Extracellular By similarity
	Transmembrane	158 – 179	22	Helical; Name=M2; By similarity
	Topological domain	180 – 427	248	Cytoplasmic By similarity
	Motif	143 – 148	6	Selectivity filter By similarity
	Motif	425 – 427	3	PDZ-binding Potential
Sites
	Site	173	1	Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesium By similarity
Amino acid modifications
	Modified residue	400	1	Phosphoserine By similarity

Sequences

	Sequence		Length	Mass (Da)
	P52188 [UniParc]. Last modified October 1, 1996. Version 1. Checksum: 6FA100FEB6066677	FASTA	427	48,399
	10 20 30 40 50 60 MTAASRANPY SIVSSEEDGL HLVTMSGANG FGNGKVHTRR RCRNRFVKKN GQCNIEFANM 70 80 90 100 110 120 DEKSQRYLAD MFTTCVDIRW RYMLLIFSLA FLASWLLFGI IFWVIAVAHG DLEPAEGRGR 130 140 150 160 170 180 TPCVLQVHGF MAAFLFSIET QTTIGYGLRC VTEECPVAVF MVVAQSIVGC IIDSFMIGAI 190 200 210 220 230 240 MAKMGRPKKR AQTLLFSHNA VVALRDGKLC LMWRVGNLRK SHIVEAHVRA QLIKPRVTEE 250 260 270 280 290 300 GEYIPLDQID IDVGFDKGLD RIFLVSPITI LHEIDEASPL FGISRQDLET DDFEIVVILE 310 320 330 340 350 360 GMVEATAMTT QARSSYLANE ILWGHRFEPV LFEEKNQYKI DYSHFHKTYE VPSTPRCSAK 370 380 390 400 410 420 DLVENKFLLP SANSFCYENE LAFLSRDEED EVATDRDGRS PQPEHDFDRL QASSGALERP YRRESEI

References

[1]	"Molecular cloning, functional expression and localization of a novel inward rectifier potassium channel in the rat brain." Koyama H., Morishige K., Takahashi N., Zanelli J.S., Fass D.N., Kurachi Y. FEBS Lett. 341:303-307(1994) [PubMed: 8137958] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Brain.
[2]	"A multiprotein trafficking complex composed of SAP97, CASK, Veli, and Mint1 is associated with inward rectifier Kir2 potassium channels." Leonoudakis D., Conti L.R., Radeke C.M., McGuire L.M., Vandenberg C.A. J. Biol. Chem. 279:19051-19063(2004) [PubMed: 14960569] [Abstract] Cited for: INTERACTION WITH CASK; LIN7A; LIN7B; LIN7C; APBA1 AND DLG1, FUNCTION.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X78461 mRNA. Translation: CAA55216.1.
IPI	IPI00777371.
PIR	S43667.
UniGene	Rn.10406.
3D structure databases
ProteinModelPortal	P52188.
SMR	P52188. Positions 188-369.
ModBase	Search...
Protein-protein interaction databases
IntAct	P52188. 8 interactions.
MINT	MINT-158957.
STRING	P52188.
PTM databases
PhosphoSite	P52188.
Proteomic databases
PRIDE	P52188.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
UCSC	NM_053981. rat.
Organism-specific databases
RGD	621660. Kcnj12.
Phylogenomic databases
eggNOG	maNOG08081.
HOVERGEN	HBG006178.
InParanoid	P52188.
OrthoDB	EOG4N04DV.
Gene expression databases
ArrayExpress	P52188.
Genevestigator	P52188.
GermOnline	ENSRNOG00000002303. Rattus norvegicus.
Family and domain databases
InterPro	IPR014756. Ig_E-set. IPR016449. K_chnl_inward-rec_Kir. IPR001838. K_chnl_inward-rec_Kir-like. IPR003272. K_chnl_inward-rec_Kir2.2. IPR013521. K_chnl_inward-rec_Kir_Cr2. IPR013518. K_chnl_inward-rec_Kir_cyto. IPR013673. K_chnl_inward-rec_Kir_N. [Graphical view]
Gene3D	G3DSA:2.60.40.1400. IR_K+channel_cytopl. 1 hit.
PANTHER	PTHR11767. K+channel_IR. 1 hit. PTHR11767:SF14. KIR22_channel. 1 hit.
Pfam	PF01007. IRK. 1 hit. PF08466. IRK_N. 1 hit. [Graphical view]
PIRSF	PIRSF005465. GIRK_kir. 1 hit.
PRINTS	PR01325. KIR22CHANNEL. PR01320. KIRCHANNEL.
SUPFAM	SSF81296. Ig_E-set. 1 hit.
ProtoNet	Search...

Entry information

Entry name

IRK12_RAT

Accession

Primary (citable) accession number: P52188

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1996
Last sequence update:	October 1, 1996
Last modified:	September 21, 2011
This is version 92 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program