O60928 (IRK13_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Inward rectifier potassium channel 13

Alternative name(s):
Inward rectifier K(+) channel Kir7.1
Potassium channel, inwardly rectifying subfamily J member 13

Gene names

Name:

KCNJ13

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	360 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	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. KCNJ13 has a very low single channel conductance, low sensitivity to block by external barium and cesium, and no dependence of its inward rectification properties on the internal blocking particle magnesium.
Subcellular location	Membrane; Multi-pass membrane protein.
Tissue specificity	Predominantly expressed in small intestine. Expression is also detected in stomach, kidney, and all central nervous system regions tested with the exception of spinal cord.
Involvement in disease	Defects in KCNJ13 are the cause of snowflake vitreoretinal degeneration (SVD) [MIM:193230]. SVD is a developmental and progressive hereditary eye disorder that affects multiple tissues within the eye. Diagnostic features of SVD include fibrillar degeneration of the vitreous humor, early-onset cataract, minute crystalline deposits in the neurosensory retina, and retinal detachment. Ref.8 Defects in KCNJ13 are the cause of Leber congenital amaurosis type 16 (LCA16) [MIM:614186]. LCA16 is a severe dystrophy of the retina, typically becoming evident in the first years of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia and keratoconus. Ref.9
Sequence similarities	Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ13 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Potassium transport Transport
Cellular component	Membrane
Coding sequence diversity	Polymorphism
Disease	Cataract Disease mutation Leber congenital amaurosis
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	voltage-gated potassium channel complex Non-traceable author statement. Source: UniProtKB
Molecular function	inward rectifier potassium channel activity Non-traceable author statement Ref.1. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 360	360	Inward rectifier potassium channel 13		PRO_0000154966
Regions
	Topological domain	1 – 53	53	Cytoplasmic By similarity
	Transmembrane	54 – 78	25	Helical; Name=M1; By similarity
	Topological domain	79 – 105	27	Extracellular By similarity
	Intramembrane	106 – 117	12	Helical; Pore-forming; Name=H5; By similarity
	Intramembrane	118 – 124	7	Pore-forming; By similarity
	Topological domain	125 – 133	9	Extracellular By similarity
	Transmembrane	134 – 155	22	Helical; Name=M2; By similarity
	Topological domain	156 – 360	205	Cytoplasmic By similarity
	Motif	119 – 124	6	Selectivity filter By similarity
Sites
	Site	149	1	Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesium By similarity
Amino acid modifications
	Modified residue	327	1	Phosphothreonine By similarity
Natural variations
	Natural variant	117	1	Q → R in LCA16. Ref.9		VAR_066488
	Natural variant	162	1	R → Q Found in a patient with autosomal recessive retinitis pigmentosa. Ref.9		VAR_066489
	Natural variant	162	1	R → W in SVD; overexpression produces a non-selective cation current that depolarizes transfected cells and increases their fragility. Ref.8		VAR_043509
	Natural variant	175	1	T → I. Ref.1 Ref.6 Corresponds to variant rs1801251 [ dbSNP | Ensembl ].		VAR_016193
	Natural variant	241	1	L → P in LCA16. Ref.9		VAR_066490
	Natural variant	276	1	E → A Found in a patient with autosomal recessive retinitis pigmentosa. Ref.9		VAR_066491
	Natural variant	290	1	P → Q. Ref.6 Corresponds to variant rs17853727 [ dbSNP | Ensembl ].		VAR_043510
	Natural variant	309	1	G → C. Ref.6 Corresponds to variant rs17857137 [ dbSNP | Ensembl ].		VAR_043511

Sequences

	Sequence		Length	Mass (Da)
	O60928 [UniParc]. Last modified August 1, 1998. Version 1. Checksum: 0C49D0DBC619BC50	FASTA	360	40,530
	10 20 30 40 50 60 MDSSNCKVIA PLLSQRYRRM VTKDGHSTLQ MDGAQRGLAY LRDAWGILMD MRWRWMMLVF 70 80 90 100 110 120 SASFVVHWLV FAVLWYVLAE MNGDLELDHD APPENHTICV KYITSFTAAF SFSLETQLTI 130 140 150 160 170 180 GYGTMFPSGD CPSAIALLAI QMLLGLMLEA FITGAFVAKI ARPKNRAFSI RFTDTAVVAH 190 200 210 220 230 240 MDGKPNLIFQ VANTRPSPLT SVRVSAVLYQ ERENGKLYQT SVDFHLDGIS SDECPFFIFP 250 260 270 280 290 300 LTYYHSITPS SPLATLLQHE NPSHFELVVF LSAMQEGTGE ICQRRTSYLP SEIMLHHCFA 310 320 330 340 350 360 SLLTRGSKGE YQIKMENFDK TVPEFPTPLV SKSPNRTDLD IHINGQSIDN FQISETGLTE

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Cloning and characterization of a novel human inwardly rectifying potassium channel predominantly expressed in small intestine." Partiseti M., Collura V., Agnel M., Culouscou J.-M., Graham D. FEBS Lett. 434:171-176(1998) [PubMed: 9738472] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], VARIANT ILE-175. Tissue: Brain.
[2]	"A novel inward rectifier K+ channel with unique pore properties." Krapivinsky G., Medina I., Eng L., Krapivinsky L., Yang Y., Clapham D.E. Neuron 20:995-1005(1998) [PubMed: 9620703] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Brain.
[3]	Hirose S., Suzuki Y., Nakamura N. Submitted (MAY-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Small intestine.
[4]	Nakamura N., Matsuki T., Suzuki Y., Sakuta H., Ito T., Hirose S. Submitted (MAY-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[5]	"Unique epithelial Kir7.1 subunit defines a new subfamily of inwardly rectifying potassium channels." Doering F., Derst C., Wischmeyer E., Karschin C., Daut J., Karschin A. Submitted (MAY-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Testis.
[6]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], VARIANTS ILE-175; GLN-290 AND CYS-309. Tissue: Brain.
[7]	"Partial gene structure and assignment to chromosome 2q37 of the human inwardly rectifying K+ channel (Kir7.1) gene (KCNJ13)." Derst C., Doring F., Preisig-M ueller R., Daut J., Karschin A., Jeck N., Weber S., Engel H., Grzeschik K.-H. Genomics 54:560-563(1998) [PubMed: 9878260] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 147-175.
[8]	"Mutations in KCNJ13 cause autosomal-dominant snowflake vitreoretinal degeneration." Hejtmancik J.F., Jiao X., Li A., Sergeev Y.V., Ding X., Sharma A.K., Chan C.-C., Medina I., Edwards A.O. Am. J. Hum. Genet. 82:174-180(2008) [PubMed: 18179896] [Abstract] Cited for: VARIANT SVD TRP-162, CHARACTERIZATION OF VARIANT SVD TRP-162.
[9]	"Recessive mutations in KCNJ13, encoding an inwardly rectifying potassium channel subunit, cause leber congenital amaurosis." Sergouniotis P.I., Davidson A.E., Mackay D.S., Li Z., Yang X., Plagnol V., Moore A.T., Webster A.R. Am. J. Hum. Genet. 89:183-190(2011) [PubMed: 21763485] [Abstract] Cited for: VARIANTS LCA16 ARG-117 AND PRO-241, VARIANTS GLN-162 AND ALA-276.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AJ007557 mRNA. Translation: CAA07552.1. AF061118 mRNA. Translation: AAC15769.1. AB013889 mRNA. Translation: BAA28271.1. AB013891 mRNA. Translation: BAA28273.1. AJ006128 mRNA. Translation: CAA06878.1. BC037290 mRNA. Translation: AAH37290.1. AF082182 Genomic DNA. Translation: AAD08673.1.
IPI	IPI00000058.
RefSeq	NP_001165887.1. NM_001172416.1. NP_001165888.1. NM_001172417.1. NP_002233.2. NM_002242.4.
UniGene	Hs.467338.
3D structure databases
ProteinModelPortal	O60928.
SMR	O60928. Positions 17-344.
ModBase	Search...
Protein-protein interaction databases
STRING	O60928.
Protein family/group databases
TCDB	1.A.2.1.8. inward rectifier K+ channel (IRK-C) family.
PTM databases
PhosphoSite	O60928.
Proteomic databases
PRIDE	O60928.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENST00000233826; ENSP00000233826; ENSG00000115474. ENST00000410029; ENSP00000386251; ENSG00000115474.
GeneID	3769.
KEGG	hsa:3769.
UCSC	uc002vto.2. human.
Organism-specific databases
CTD	3769.
GeneCards	GC02M233630.
H-InvDB	HIX0023903.
HGNC	HGNC:6259. KCNJ13.
MIM	193230. phenotype. 603208. gene. 614186. phenotype.
neXtProt	NX_O60928.
Orphanet	65. Congenital Leber amaurosis. 91496. Snowflake vitreoretinal degeneration.
GenAtlas	Search...
Phylogenomic databases
eggNOG	prNOG19555.
HOGENOM	HBG716702.
HOVERGEN	HBG006178.
InParanoid	O60928.
OMA	YYHSITP.
OrthoDB	EOG44J2JS.
PhylomeDB	O60928.
Gene expression databases
ArrayExpress	O60928.
Bgee	O60928.
CleanEx	HS_KCNJ13.
Genevestigator	O60928.
GermOnline	ENSG00000115474. Homo sapiens.
Family and domain databases
InterPro	IPR014756. Ig_E-set. IPR016449. K_chnl_inward-rec_Kir. IPR001838. K_chnl_inward-rec_Kir-like. IPR008062. K_chnl_inward-rec_Kir7. IPR013521. K_chnl_inward-rec_Kir_Cr2. IPR013518. K_chnl_inward-rec_Kir_cyto. [Graphical view]
Gene3D	G3DSA:2.60.40.1400. IR_K+channel_cytopl. 1 hit.
KO	K05006.
PANTHER	PTHR11767. K+channel_IR. 1 hit. PTHR11767:SF3. KIR7_channel. 1 hit.
Pfam	PF01007. IRK. 1 hit. [Graphical view]
PIRSF	PIRSF005465. GIRK_kir. 1 hit.
PRINTS	PR01679. KIR7CHANNEL. PR01320. KIRCHANNEL.
SUPFAM	SSF81296. Ig_E-set. 1 hit.
ProtoNet	Search...
Other
NextBio	14781.
SOURCE	Search...

Entry information

Entry name

IRK13_HUMAN

Accession

Primary (citable) accession number: O60928
Secondary accession number(s): O76023, Q8N3Y4

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 27, 2001
Last sequence update:	August 1, 1998
Last modified:	January 25, 2012
This is version 110 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.