Q9QYW1 (KCNN4_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Intermediate conductance calcium-activated potassium channel protein 4
Short name=SK4
Short name=SKCa 4
Short name=SKCa4

Alternative name(s):
IK1
KCa3.1
KCa4

Gene names

Name:	Kcnn4
Synonyms:	Ik1, Sk4, Smik

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

General annotation (Comments)

Function	Forms a voltage-independent potassium channel that is activated by intracellular calcium. Activation is followed by membrane hyperpolarization which promotes calcium influx. Required for maximal calcium influx and proliferation during the reactivation of naive T cells. The channel is blocked by clotrimazole and charybdotoxin but is insensitive to apamin By similarity.
Subunit structure	Heterotetramer of potassium channel proteins Probable. Interacts with MTMR6 By similarity.
Subcellular location	Membrane; Multi-pass membrane protein.
Post-translational modification	Phosphorylation at His-356 by NDKB activates the channel, and conversely it's dephosphorylation by PHPT1 inhibits the channel By similarity.
Sequence similarities	Belongs to the potassium channel KCNN family. KCa3.1/KCNN4 subfamily.

Ontologies

Keywords
Biological process	Immunity Ion transport Transport
Cellular component	Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Calmodulin-binding
Molecular function	Ionic channel
PTM	Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Cellular component	integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	calcium-activated potassium channel activity Inferred from direct assay Ref.1. Source: RGD calmodulin binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 425	425	Intermediate conductance calcium-activated potassium channel protein 4		PRO_0000155019
Regions
	Transmembrane	30 – 50	21	Helical; Name=Segment S1; Potential
	Transmembrane	59 – 79	21	Helical; Name=Segment S2; Potential
	Transmembrane	105 – 121	17	Helical; Name=Segment S3; Potential
	Transmembrane	141 – 161	21	Helical; Name=Segment S4; Potential
	Transmembrane	205 – 225	21	Helical; Name=Segment S5; Potential
	Intramembrane	239 – 259	21	Pore-forming; Name=Segment H5; Potential
	Transmembrane	263 – 283	21	Helical; Name=Segment S6; Potential
	Region	284 – 345	62	Calmodulin-binding By similarity
	Compositional bias	413 – 416	4	Poly-Gln
Amino acid modifications
	Modified residue	356	1	Phosphohistidine By similarity
Experimental info
	Sequence conflict	213	1	L → F in CAB40141. Ref.2
	Sequence conflict	280	1	V → L in AAD38205. Ref.4
	Sequence conflict	395	1	D → H in AAD38205. Ref.4
	Sequence conflict	399	1	G → R in AAD38205. Ref.4
	Sequence conflict	410	1	T → S in AAD38205. Ref.4
	Sequence conflict	416	1	Missing in AAD38205. Ref.4

Sequences

	Sequence		Length	Mass (Da)
	Q9QYW1 [UniParc]. Last modified November 16, 2001. Version 2. Checksum: E861DB088D20D8FC	FASTA	425	47,767
	10 20 30 40 50 60 MGGELVTGLG ALRRRKRLLE QEKRVAGWAL VLAGTGIGLM VLHAEMLWFL GCKWVLYLLL 70 80 90 100 110 120 VKCLITLSTA FLLCLIVVFH AKEVQLFMTD NGLRDWRVAL TRRQVAQILL ELLVCGVHPV 130 140 150 160 170 180 PLRSPHCTLA GEATDSQAWP GFLGEGEALL SLAMLLRLYL VPRAVLLRSG VLLNASYRSI 190 200 210 220 230 240 GALNQVRFRH WFVAKLYMNT HPGRLLLGLT LGLWLTTAWV LSVAERQAVN ATGHLTDTLW 250 260 270 280 290 300 LIPITFLTIG YGDVVPGTLW GKIVCLCTGV MGVCCTALLV AVVARKLEFN KAEKHVHNFM 310 320 330 340 350 360 MDIHYAKEMK ESAARLLQEA WMYYKHTRRK DSRAARRHQR KMLAAIHTFR QVRLKHRKLR 370 380 390 400 410 420 EQVNSMVDIS KMHMILCDLQ LGLSASHLAL EKRIDGLAGK LDALTELLST ALQQQQPPEP IQEAT

References

[1]	"Molecular cloning and characterization of the intermediate-conductance Ca(2+)-activated K(+) channel in vascular smooth muscle: relationship between K(Ca) channel diversity and smooth muscle cell function." Neylon C., Lang R.J., Fu Y., Bobik A., Reinhart P.H. Circ. Res. 85:E33-E43(1999) [PubMed: 10532960] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Wistar Kyoto. Tissue: Aortic smooth muscle.
[2]	"Molecular and functional characterization of the small Ca2+-regulated K+ channel (rSK4) of colonic crypts." Warth R., Hamm K., Bleich M., Kunzelmann K., von Hahn T., Schreiber R., Ullrich E., Mengel M., Trautmann N., Kindle P., Schwab A., Greger R. Pflugers Arch. 438:437-444(1999) [PubMed: 10519135] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Wistar. Tissue: Colon.
[3]	"Rat intermediate conductance calcium-activated potassium channel." Fujiwara Y., Saito T., Sasamura R., Miura M. Submitted (MAY-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Sprague-Dawley.
[4]	"cDNA cloning of an intermediate conductance Ca2+-activated K+ channel (rIK1) and its regulation by dietary K-depletion in rat distal colon." Rajendran V.M., Sangan P., Joiner W.J., Binder H.J. Submitted (JUN-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Sprague-Dawley.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF190458 mRNA. Translation: AAF05602.1. AF149250 mRNA. Translation: AAD38032.1. AJ133438 mRNA. Translation: CAB40141.2. AF156554 mRNA. Translation: AAD38205.1.
IPI	IPI00214489.
RefSeq	NP_075410.1. NM_023021.1.
UniGene	Rn.44212.
3D structure databases
ProteinModelPortal	Q9QYW1.
ModBase	Search...
Protein-protein interaction databases
STRING	Q9QYW1.
PTM databases
PhosphoSite	Q9QYW1.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	65206.
KEGG	rno:65206.
Organism-specific databases
CTD	3783.
RGD	621476. Kcnn4.
Phylogenomic databases
GeneTree	ENSGT00500000044784.
HOVERGEN	HBG052241.
OrthoDB	EOG42FSHQ.
Gene expression databases
Genevestigator	Q9QYW1.
GermOnline	ENSRNOG00000019440. Rattus norvegicus.
Family and domain databases
InterPro	IPR004178. CaM-bd_dom. IPR013099. Ion_trans_2. IPR015449. K_chnl_Ca-activ_SK. [Graphical view]
KO	K04945.
PANTHER	PTHR10153. CaKChannelSK. 1 hit.
Pfam	PF02888. CaMBD. 1 hit. PF07885. Ion_trans_2. 1 hit. PF03530. SK_channel. 1 hit. [Graphical view]
SMART	SM01053. CaMBD. 1 hit. [Graphical view]
SUPFAM	SSF81327. CaM_bd. 1 hit.
ProtoNet	Search...
Other
NextBio	614173.

Entry information

Entry name

KCNN4_RAT

Accession

Primary (citable) accession number: Q9QYW1
Secondary accession number(s): Q9R198, Q9WVA5

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 16, 2001
Last sequence update:	November 16, 2001
Last modified:	January 25, 2012
This is version 89 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program