P70604 (KCNN2_RAT) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Small conductance calcium-activated potassium channel protein 2
Short name=SK2
Short name=SKCa 2
Short name=SKCa2

Alternative name(s):
KCa2.2

Gene names

Name:

Kcnn2

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	580 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin.
Subunit structure	Heterooligomer. The complex is composed of 4 channel subunits each of which binds to a calmodulin subunit which regulates the channel activity through calcium-binding.
Subcellular location	Membrane; Multi-pass membrane protein.
Tissue specificity	Brain.
Sequence similarities	Belongs to the potassium channel KCNN family. KCa2.2/KCNN2 subfamily.

Ontologies

Keywords
Biological process	Ion transport Transport
Cellular component	Membrane
Domain	Transmembrane Transmembrane helix
Ligand	Calmodulin-binding
Molecular function	Ionic channel
Technical term	3D-structure Complete proteome Reference proteome
Gene Ontology (GO)
Cellular component	integral to membrane Inferred from direct assay Ref.3. Source: UniProtKB
Molecular function	calmodulin binding Inferred from electronic annotation. Source: UniProtKB-KW small conductance calcium-activated potassium channel activity Inferred from direct assay Ref.3. Source: UniProtKB
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
Calm1	P62161	2	EBI-1031103,EBI-397530

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 580

580

Small conductance calcium-activated potassium channel protein 2

PRO_0000155012

Regions

Transmembrane

140 – 160

21

Helical; Name=Segment S1; Potential

Transmembrane

169 – 189

21

Helical; Name=Segment S2; Potential

Transmembrane

215 – 235

21

Helical; Name=Segment S3; Potential

Transmembrane

257 – 277

21

Helical; Name=Segment S4; Potential

Transmembrane

306 – 326

21

Helical; Name=Segment S5; Potential

Intramembrane

346 – 366

21

Pore-forming; Name=Segment H5; Potential

Transmembrane

375 – 395

21

Helical; Name=Segment S6; Potential

Region

413 – 489

77

Calmodulin-binding

Compositional bias

42 – 46

5

Poly-Gly

Compositional bias

52 – 56

5

Poly-Ala

Compositional bias

80 – 85

6

Poly-Gly

Compositional bias

88 – 103

16

Poly-Gly

Compositional bias

564 – 567

4

Poly-Arg

Secondary structure

1

.

.

.

.

.

.

.

.

.

580

Helix Strand Turn

Details...

Beta strand

398 – 401

4

Helix

414 – 439

26

Helix

446 – 485

40

Helix

489 – 523

35

Sequences

	Sequence		Length	Mass (Da)
	P70604 [UniParc]. Last modified February 1, 1997. Version 1. Checksum: F71E0DAF7EEFA8D4	FASTA	580	63,848
	10 20 30 40 50 60 MSSCRYNGGV MRPLSNLSSS RRNLHEMDSE AQPLQPPASV VGGGGGASSP SAAAAASSSA 70 80 90 100 110 120 PEIVVSKPEH NNSNNLALYG TGGGGSTGGG GGGGGGGGGS GHGSSSGTKS SKKKNQNIGY 130 140 150 160 170 180 KLGHRRALFE KRKRLSDYAL IFGMFGIVVM VIETELSWGA YDKASLYSLA LKCLISLSTI 190 200 210 220 230 240 ILLGLIIVYH AREIQLFMVD NGADDWRIAM TYERIFFICL EILVCAIHPI PGNYTFTWTA 250 260 270 280 290 300 RLAFSYAPST TTADVDIILS IPMFLRLYLI ARVMLLHSKL FTDASSRSIG ALNKINFNTR 310 320 330 340 350 360 FVMKTLMTIC PGTVLLVFSI SLWIIAAWTV RACERYHDQQ DVTSNFLGAM WLISITFLSI 370 380 390 400 410 420 GYGDMVPNTY CGKGVCLLTG IMGAGCTALV VAVVARKLEL TKAEKHVHNF MMDTQLTKRV 430 440 450 460 470 480 KNAAANVLRE TWLIYKNTKL VKKIDHAKVR KHQRKFLQAI HQLRSVKMEQ RKLNDQANTL 490 500 510 520 530 540 VDLAKTQNIM YDMISDLNER SEDFEKRIVT LETKLETLIG SIHALPGLIS QTIRQQQRDF 550 560 570 580 IETQMENYDK HVTYNAERSR SSSRRRRSSS TAPPTSSESS

References

[1]	"Small-conductance, calcium-activated potassium channels from mammalian brain." Koehler M., Hirschberg B., Bond C.T., Kinzie J.M., Marrion N.V., Maylie J., Adelman J.P. Science 273:1709-1714(1996) [PubMed: 8781233] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Strain: Sprague-Dawley. Tissue: Brain.
[2]	"Mechanism of calcium gating in small-conductance calcium-activated potassium channels." Xia X.M., Fakler B., Rivard A.F., Wayman G., Johnson-Pais T., Keen J.E., Ishii T., Hirschberg B., Bond C.T., Lutsenko S., Maylie J., Adelman J.P. Nature 395:503-507(1998) [PubMed: 9774106] [Abstract] Cited for: INTERACTION WITH CALMODULIN.
[3]	"Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin." Schumacher M.A., Rivard A.F., Bachinger H.P., Adelman J.P. Nature 410:1120-1124(2001) [PubMed: 11323678] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS) OF 395-490 WITH CALMODULIN.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

U69882 mRNA. Translation: AAB09563.1.

IPI

IPI00190493.

RefSeq

NP_062187.1. NM_019314.1.

UniGene

Rn.44421.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1G4Y	X-ray	1.60	B	396-487	[»]
1KKD	NMR	-	A	396-487	[»]
1QX7	X-ray	3.09	D	411-487	[»]
2PNV	X-ray	2.10	A/B	488-526	[»]

ProteinModelPortal

P70604.

SMR

P70604. Positions 396-526.

ModBase

Search...

Protein-protein interaction databases

IntAct

P70604. 1 interaction.

MINT

MINT-197486.

STRING

P70604.

PTM databases

PhosphoSite

P70604.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

Ensembl

ENSRNOT00000022530; ENSRNOP00000022530; ENSRNOG00000016675.

GeneID

54262.

KEGG

rno:54262.

UCSC

NM_019314. rat.

Organism-specific databases

CTD

3781.

RGD

2963. Kcnn2.

Phylogenomic databases

eggNOG

roNOG05804.

HOVERGEN

HBG052241.

InParanoid

P70604.

OrthoDB

EOG49CQ7G.

Gene expression databases

ArrayExpress

P70604.

Genevestigator

P70604.

GermOnline

ENSRNOG00000016675. Rattus norvegicus.

Family and domain databases

InterPro

IPR004178. CaM-bd_dom.
IPR013099. Ion_trans_2.
IPR015449. K_chnl_Ca-activ_SK.
[Graphical view]

KO

K04943.

PANTHER

PTHR10153. CaKChannelSK. 1 hit.

Pfam

PF02888. CaMBD. 1 hit.
PF07885. Ion_trans_2. 1 hit.
PF03530. SK_channel. 1 hit.
[Graphical view]

PRINTS

PR01451. SKCHANNEL.

SMART

SM01053. CaMBD. 1 hit.
[Graphical view]

SUPFAM

SSF81327. CaM_bd. 1 hit.

ProtoNet

Search...

Other

NextBio

610790.

Entry information

Entry name

KCNN2_RAT

Accession

Primary (citable) accession number: P70604

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 16, 2001
Last sequence update:	February 1, 1997
Last modified:	January 25, 2012
This is version 93 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program