P35560 (IRK1_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
ATP-sensitive inward rectifier potassium channel 1

Alternative name(s):
ATP-regulated potassium channel ROM-K
Inward rectifier K(+) channel Kir1.1
KAB-1
Potassium channel, inwardly rectifying subfamily J member 1

Gene names

Name:	Kcnj1
Synonyms:	Romk1

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	391 AA.
Sequence status	Complete.
Protein existence	Evidence at transcript level

General annotation (Comments)

Function	In the kidney, probably plays a major role in potassium homeostasis. 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. This channel is activated by internal ATP and can be blocked by external barium.
Enzyme regulation	Inhibited by WNK3 By similarity.
Subunit structure	Interacts with SGK1 and SLC9A3R2/NHERF2 By similarity.
Subcellular location	Cell membrane; Multi-pass membrane protein. Note: Phosphorylation at Ser-44 by SGK1 is necessary for its expression at the cell membrane By similarity.
Tissue specificity	Mainly in kidney (renal cortex, medulla and papilla). In the brain, found in the cortex and the hippocampus.
Post-translational modification	Phosphorylation at Ser-44 by SGK1 is necessary for its expression at the cell membrane By similarity.
Sequence similarities	Belongs to the inward rectifier-type potassium channel (TC 1.A.2.1) family. KCNJ1 subfamily. [View classification]

Ontologies

Keywords
Biological process	Ion transport Potassium transport Transport
Cellular component	Cell membrane Membrane
Coding sequence diversity	Alternative splicing
Domain	Transmembrane Transmembrane helix
Ligand	ATP-binding Nucleotide-binding Potassium
Molecular function	Ion channel Voltage-gated channel
PTM	Glycoprotein Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Cellular_component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW plasma membrane Inferred from direct assay PubMed 16906771. Source: RGD
Molecular_function	ATP binding Inferred from electronic annotation. Source: UniProtKB-KW ATP-activated inward rectifier potassium channel activity Inferred from direct assay PubMed 7611454. Source: RGD peptide binding Inferred from direct assay PubMed 16906771. Source: RGD potassium ion binding Inferred from mutant phenotype PubMed 16906771. Source: RGD
Complete GO annotation...

Alternative products

This entry describes 6 isoforms produced by alternative splicing. [Align] [Select]

Isoform A (identifier: P35560-1)

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 B (identifier: P35560-2)

Also known as: ROMK2;

The sequence of this isoform differs from the canonical sequence as follows:
     1-19: Missing.

Isoform C (identifier: P35560-3)

Also known as: ROMK3;

The sequence of this isoform differs from the canonical sequence as follows:
     1-12: MGASERSVFRVL → MVSELSIPSIPTGVAGLSK

Isoform D (identifier: P35560-4)

Also known as: 1.1; ROMK1.1;

The sequence of this isoform differs from the canonical sequence as follows:
     79-124: YKMTVFITAF...PDNRTPCVEN → DSSDHRLRIQ...HVWCHFSQDL
     125-391: Missing.

Isoform E (identifier: P35560-5)

Also known as: 3.1; ROMK3.1;

The sequence of this isoform differs from the canonical sequence as follows:
     1-12: MGASERSVFRVL → MVSELSIPSIPTGVAGLSK
     79-124: YKMTVFITAF...PDNRTPCVEN → DSSDHRLRIQ...HVWCHFSQDL
     125-391: Missing.

Isoform F (identifier: P35560-6)

Also known as: 6.1; ROMK6.1;

The sequence of this isoform differs from the canonical sequence as follows:
     1-19: Missing.
     79-124: YKMTVFITAF...PDNRTPCVEN → DSSDHRLRIQ...HVWCHFSQDL
     125-391: Missing.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 391	391	ATP-sensitive inward rectifier potassium channel 1		PRO_0000154919
Regions
	Topological domain	1 – 77	77	Cytoplasmic By similarity
	Transmembrane	78 – 102	25	Helical; Name=M1; By similarity
	Topological domain	103 – 127	25	Extracellular By similarity
	Intramembrane	128 – 139	12	Helical; Pore-forming; Name=H5; By similarity
	Intramembrane	140 – 146	7	Pore-forming; By similarity
	Topological domain	147 – 155	9	Extracellular By similarity
	Transmembrane	156 – 177	22	Helical; Name=M2; By similarity
	Topological domain	178 – 391	214	Cytoplasmic By similarity
	Nucleotide binding	223 – 230	8	ATP Potential
	Motif	141 – 146	6	Selectivity filter By similarity
Sites
	Site	171	1	Role in the control of polyamine-mediated channel gating and in the blocking by intracellular magnesium By similarity
Amino acid modifications
	Modified residue	44	1	Phosphoserine; by SGK1 By similarity
	Glycosylation	117	1	N-linked (GlcNAc...) Potential
Natural variations
	Alternative sequence	1 – 19	19	Missing in isoform B and isoform F.		VSP_002799
	Alternative sequence	1 – 12	12	MGASE…VFRVL → MVSELSIPSIPTGVAGLSK in isoform C and isoform E.		VSP_002800
	Alternative sequence	79 – 124	46	YKMTV…PCVEN → DSSDHRLRIQVCDRTVRHCH FPAYLPVYSWSDHQFLHVWC HFSQDL in isoform D, isoform E and isoform F.		VSP_002801
	Alternative sequence	125 – 391	267	Missing in isoform D, isoform E and isoform F.		VSP_002802

Sequences

	Sequence		Length	Mass (Da)
	Isoform A [UniParc]. Last modified June 1, 1994. Version 1. Checksum: 896FD0FD128F85D0	FASTA	391	44,963
	10 20 30 40 50 60 MGASERSVFR VLIRALTERM FKHLRRWFIT HIFGRSRQRA RLVSKEGRCN IEFGNVDAQS 70 80 90 100 110 120 RFIFFVDIWT TVLDLKWRYK MTVFITAFLG SWFLFGLLWY VVAYVHKDLP EFYPPDNRTP 130 140 150 160 170 180 CVENINGMTS AFLFSLETQV TIGYGFRFVT EQCATAIFLL IFQSILGVII NSFMCGAILA 190 200 210 220 230 240 KISRPKKRAK TITFSKNAVI SKRGGKLCLL IRVANLRKSL LIGSHIYGKL LKTTITPEGE 250 260 270 280 290 300 TIILDQTNIN FVVDAGNENL FFISPLTIYH IIDHNSPFFH MAAETLSQQD FELVVFLDGT 310 320 330 340 350 360 VESTSATCQV RTSYVPEEVL WGYRFVPIVS KTKEGKYRVD FHNFGKTVEV ETPHCAMCLY 370 380 390 NEKDARARMK RGYDNPNFVL SEVDETDDTQ M
	Isoform B (ROMK2) [UniParc]. Checksum: 413C456ED8945C98	FASTA	372	42,790
	10 20 30 40 50 60 MFKHLRRWFI THIFGRSRQR ARLVSKEGRC NIEFGNVDAQ SRFIFFVDIW TTVLDLKWRY 70 80 90 100 110 120 KMTVFITAFL GSWFLFGLLW YVVAYVHKDL PEFYPPDNRT PCVENINGMT SAFLFSLETQ 130 140 150 160 170 180 VTIGYGFRFV TEQCATAIFL LIFQSILGVI INSFMCGAIL AKISRPKKRA KTITFSKNAV 190 200 210 220 230 240 ISKRGGKLCL LIRVANLRKS LLIGSHIYGK LLKTTITPEG ETIILDQTNI NFVVDAGNEN 250 260 270 280 290 300 LFFISPLTIY HIIDHNSPFF HMAAETLSQQ DFELVVFLDG TVESTSATCQ VRTSYVPEEV 310 320 330 340 350 360 LWGYRFVPIV SKTKEGKYRV DFHNFGKTVE VETPHCAMCL YNEKDARARM KRGYDNPNFV 370 LSEVDETDDT QM
	Isoform C (ROMK3) [UniParc]. Checksum: BF9FAC45A8C17863	FASTA	398	45,498
	10 20 30 40 50 60 MVSELSIPSI PTGVAGLSKI RALTERMFKH LRRWFITHIF GRSRQRARLV SKEGRCNIEF 70 80 90 100 110 120 GNVDAQSRFI FFVDIWTTVL DLKWRYKMTV FITAFLGSWF LFGLLWYVVA YVHKDLPEFY 130 140 150 160 170 180 PPDNRTPCVE NINGMTSAFL FSLETQVTIG YGFRFVTEQC ATAIFLLIFQ SILGVIINSF 190 200 210 220 230 240 MCGAILAKIS RPKKRAKTIT FSKNAVISKR GGKLCLLIRV ANLRKSLLIG SHIYGKLLKT 250 260 270 280 290 300 TITPEGETII LDQTNINFVV DAGNENLFFI SPLTIYHIID HNSPFFHMAA ETLSQQDFEL 310 320 330 340 350 360 VVFLDGTVES TSATCQVRTS YVPEEVLWGY RFVPIVSKTK EGKYRVDFHN FGKTVEVETP 370 380 390 HCAMCLYNEK DARARMKRGY DNPNFVLSEV DETDDTQM
	Isoform D (1.1) (ROMK1.1) [UniParc]. Checksum: 80711AA2CC30B94C	FASTA	124	15,081
	10 20 30 40 50 60 MGASERSVFR VLIRALTERM FKHLRRWFIT HIFGRSRQRA RLVSKEGRCN IEFGNVDAQS 70 80 90 100 110 120 RFIFFVDIWT TVLDLKWRDS SDHRLRIQVC DRTVRHCHFP AYLPVYSWSD HQFLHVWCHF SQDL
	Isoform E (3.1) (ROMK3.1) [UniParc]. Checksum: A11E86FDBA108C45	FASTA	131	15,616
	10 20 30 40 50 60 MVSELSIPSI PTGVAGLSKI RALTERMFKH LRRWFITHIF GRSRQRARLV SKEGRCNIEF 70 80 90 100 110 120 GNVDAQSRFI FFVDIWTTVL DLKWRDSSDH RLRIQVCDRT VRHCHFPAYL PVYSWSDHQF 130 LHVWCHFSQD L
	Isoform F (6.1) (ROMK6.1) [UniParc]. Checksum: 1D01BE0092A6EE7D	FASTA	105	12,908
	10 20 30 40 50 60 MFKHLRRWFI THIFGRSRQR ARLVSKEGRC NIEFGNVDAQ SRFIFFVDIW TTVLDLKWRD 70 80 90 100 SSDHRLRIQV CDRTVRHCHF PAYLPVYSWS DHQFLHVWCH FSQDL

References

[1]	"Cloning and expression of an inwardly rectifying ATP-regulated potassium channel." Ho K., Nichols C.G., Lederer W.J., Lytton J., Vassilev P.M., Kanazirska M.V., Hebert S.C. Nature 362:31-38(1993) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Kidney.
[2]	"Primary structure and functional properties of an epithelial K channel." Zhou H., Tate S.S., Palmer L.G. Am. J. Physiol. 266:C809-C824(1994) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM B). Strain: Sprague-Dawley. Tissue: Kidney.
[3]	"Splicing of a retained intron within ROMK K+ channel RNA generates a novel set of isoforms in rat kidney." Beesley A.H., Ortega B., White S.J. Am. J. Physiol. 276:C585-C592(1999) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS D; E AND F). Strain: Wistar. Tissue: Kidney.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X72341 mRNA. Translation: CAA51068.1. L29403 mRNA. Translation: AAA50378.1. S69385 mRNA. Translation: AAB30553.1. AF081365 mRNA. Translation: AAC34443.1. AF081366 mRNA. Translation: AAC34444.1. AF081367 mRNA. Translation: AAC34445.1. AF081368 mRNA. Translation: AAC34446.1.
IPI	IPI00199632. IPI00200990. IPI00231835. IPI00231836. IPI00231837. IPI00231838.
PIR	S30046.
RefSeq	NP_058719.1. NM_017023.1.
UniGene	Rn.22609.
3D structure databases
ProteinModelPortal	P35560.
ModBase	Search...
Protein-protein interaction databases
MINT	MINT-214902.
STRING	10116.ENSRNOP00000043570.
PTM databases
PhosphoSite	P35560.
Proteomic databases
PaxDb	P35560.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	24521.
KEGG	rno:24521.
Organism-specific databases
CTD	3758.
RGD	2957. Kcnj1.
Phylogenomic databases
eggNOG	NOG247934.
HOGENOM	HOG000237326.
HOVERGEN	HBG006178.
KO	K04995.
Gene expression databases
ArrayExpress	P35560.
Genevestigator	P35560.
GermOnline	ENSRNOG00000008779. Rattus norvegicus.
Family and domain databases
Gene3D	2.60.40.1400. 1 hit.
InterPro	IPR014756. Ig_E-set. IPR016449. K_chnl_inward-rec_Kir. IPR003268. K_chnl_inward-rec_Kir1.1. IPR013518. K_chnl_inward-rec_Kir_cyto. [Graphical view]
PANTHER	PTHR11767. PTHR11767. 1 hit. PTHR11767:SF6. PTHR11767:SF6. 1 hit.
Pfam	PF01007. IRK. 1 hit. [Graphical view]
PIRSF	PIRSF005465. GIRK_kir. 1 hit.
PRINTS	PR01321. KIR11CHANNEL. PR01320. KIRCHANNEL.
SUPFAM	SSF81296. Ig_E-set. 1 hit.
ProtoNet	Search...
Other
BindingDB	P35560.
NextBio	603565.

Entry information

Entry name

IRK1_RAT

Accession

Primary (citable) accession number: P35560
Secondary accession number(s): O88639, O88640, Q9QUR5

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 1, 1994
Last sequence update:	June 1, 1994
Last modified:	May 29, 2013
This is version 106 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program