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Protein

Small conductance calcium-activated potassium channel protein 3

Gene

KCNN3

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at transcript leveli

Functioni

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.

GO - Molecular functioni

Keywordsi

Molecular functionCalmodulin-binding, Ion channel
Biological processIon transport, Transport

Enzyme and pathway databases

ReactomeiR-HSA-1296052 Ca2+ activated K+ channels

Names & Taxonomyi

Protein namesi
Recommended name:
Small conductance calcium-activated potassium channel protein 3
Short name:
SK3
Short name:
SKCa 3
Short name:
SKCa3
Alternative name(s):
KCa2.3
Gene namesi
Name:KCNN3
Synonyms:K3
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 1

Organism-specific databases

EuPathDBiHostDB:ENSG00000143603.18
HGNCiHGNC:6292 KCNN3
MIMi602983 gene
neXtProtiNX_Q9UGI6

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Transmembranei293 – 313Helical; Name=Segment S1Sequence analysisAdd BLAST21
Transmembranei320 – 340Helical; Name=Segment S2Sequence analysisAdd BLAST21
Transmembranei371 – 391Helical; Name=Segment S3Sequence analysisAdd BLAST21
Transmembranei410 – 430Helical; Name=Segment S4Sequence analysisAdd BLAST21
Transmembranei459 – 479Helical; Name=Segment S5Sequence analysisAdd BLAST21
Intramembranei499 – 519Pore-forming; Name=Segment H5Sequence analysisAdd BLAST21
Transmembranei528 – 548Helical; Name=Segment S6Sequence analysisAdd BLAST21

Keywords - Cellular componenti

Membrane

Pathology & Biotechi

Organism-specific databases

DisGeNETi3782
OpenTargetsiENSG00000143603
PharmGKBiPA30072

Chemistry databases

ChEMBLiCHEMBL3381
DrugBankiDB01110 Miconazole
DB00721 Procaine
GuidetoPHARMACOLOGYi383

Polymorphism and mutation databases

BioMutaiKCNN3
DMDMi17367120

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001550131 – 736Small conductance calcium-activated potassium channel protein 3Add BLAST736

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei172PhosphoserineBy similarity1

Keywords - PTMi

Phosphoprotein

Proteomic databases

PaxDbiQ9UGI6
PeptideAtlasiQ9UGI6
PRIDEiQ9UGI6

PTM databases

iPTMnetiQ9UGI6
PhosphoSitePlusiQ9UGI6

Expressioni

Gene expression databases

BgeeiENSG00000143603
CleanExiHS_KCNN3
ExpressionAtlasiQ9UGI6 baseline and differential
GenevisibleiQ9UGI6 HS

Organism-specific databases

HPAiHPA017990
HPA057127

Interactioni

Subunit structurei

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 (By similarity).By similarity

GO - Molecular functioni

Protein-protein interaction databases

BioGridi109983, 5 interactors
STRINGi9606.ENSP00000271915

Chemistry databases

BindingDBiQ9UGI6

Structurei

3D structure databases

ProteinModelPortaliQ9UGI6
SMRiQ9UGI6
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni566 – 642Calmodulin-bindingBy similarityAdd BLAST77

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi30 – 99Gln-richAdd BLAST70
Compositional biasi42 – 64Pro-richAdd BLAST23
Compositional biasi688 – 692Poly-Gln5
Compositional biasi732 – 735Poly-Ser4

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG3684 Eukaryota
ENOG410XT9D LUCA
GeneTreeiENSGT00500000044784
HOGENOMiHOG000276908
HOVERGENiHBG052241
InParanoidiQ9UGI6
KOiK04944
PhylomeDBiQ9UGI6
TreeFamiTF315015

Family and domain databases

InterProiView protein in InterPro
IPR004178 CaM-bd_dom
IPR036122 CaM-bd_dom_sf
IPR015449 K_chnl_Ca-activ_SK
IPR013099 K_chnl_dom
PANTHERiPTHR10153 PTHR10153, 1 hit
PfamiView protein in Pfam
PF02888 CaMBD, 1 hit
PF07885 Ion_trans_2, 1 hit
PF03530 SK_channel, 1 hit
PRINTSiPR01451 SKCHANNEL
SMARTiView protein in SMART
SM01053 CaMBD, 1 hit
SUPFAMiSSF81327 SSF81327, 1 hit

Sequences (3)i

Sequence statusi: Complete.

This entry describes 3 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: Q9UGI6-1) [UniParc]FASTAAdd to basket

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.

« Hide

        10         20         30         40         50
MDTSGHFHDS GVGDLDEDPK CPCPSSGDEQ QQQQQQQQQQ QPPPPAPPAA
60 70 80 90 100
PQQPLGPSLQ PQPPQLQQQQ QQQQQQQQQQ QQQQQPPHPL SQLAQLQSQP
110 120 130 140 150
VHPGLLHSSP TAFRAPPSSN STAILHPSSR QGSQLNLNDH LLGHSPSSTA
160 170 180 190 200
TSGPGGGSRH RQASPLVHRR DSNPFTEIAM SSCKYSGGVM KPLSRLSASR
210 220 230 240 250
RNLIEAETEG QPLQLFSPSN PPEIVISSRE DNHAHQTLLH HPNATHNHQH
260 270 280 290 300
AGTTASSTTF PKANKRKNQN IGYKLGHRRA LFEKRKRLSD YALIFGMFGI
310 320 330 340 350
VVMVIETELS WGLYSKDSMF SLALKCLISL STIILLGLII AYHTREVQLF
360 370 380 390 400
VIDNGADDWR IAMTYERILY ISLEMLVCAI HPIPGEYKFF WTARLAFSYT
410 420 430 440 450
PSRAEADVDI ILSIPMFLRL YLIARVMLLH SKLFTDASSR SIGALNKINF
460 470 480 490 500
NTRFVMKTLM TICPGTVLLV FSISLWIIAA WTVRVCERYH DQQDVTSNFL
510 520 530 540 550
GAMWLISITF LSIGYGDMVP HTYCGKGVCL LTGIMGAGCT ALVVAVVARK
560 570 580 590 600
LELTKAEKHV HNFMMDTQLT KRIKNAAANV LRETWLIYKH TKLLKKIDHA
610 620 630 640 650
KVRKHQRKFL QAIHQLRSVK MEQRKLSDQA NTLVDLSKMQ NVMYDLITEL
660 670 680 690 700
NDRSEDLEKQ IGSLESKLEH LTASFNSLPL LIADTLRQQQ QQLLSAIIEA
710 720 730
RGVSVAVGTT HTPISDSPIG VSSTSFPTPY TSSSSC
Length:736
Mass (Da):82,026
Last modified:May 1, 2000 - v1
Checksum:iCCD0CC1621FFAE9C
GO
Isoform 2 (identifier: Q9UGI6-2) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-310: Missing.
     311-315: WGLYS → MERPI

Show »
Length:426
Mass (Da):48,050
Checksum:i1EBE12900FA7719D
GO
Isoform 3 (identifier: Q9UGI6-3) [UniParc]FASTAAdd to basket
Also known as: SK3-1B

The sequence of this isoform differs from the canonical sequence as follows:
     1-318: Missing.

Note: Do not produce functional channels, but selectively suppresses endogenous SK3 currents, in a dominant-negative fashion. This dominant inhibitory effect extends to other members of the SK subfamily. Widely distributed in human tissues and is present at 20-60% of SK3 in the brain.
Show »
Length:418
Mass (Da):47,093
Checksum:iB4CD0E43E758BDC8
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti254T → A in AAC26099 (PubMed:9491810).Curated1
Sequence conflicti281L → P in AAC26099 (PubMed:9491810).Curated1
Sequence conflicti347V → A in AAC26099 (PubMed:9491810).Curated1
Sequence conflicti485V → A in AAC26099 (PubMed:9491810).Curated1

Polymorphismi

The second poly-Gln region of KCNN3 is highly polymorphic and the number of Gln varies from 12 to 28 in the population.1 Publication

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_01220481 – 85Missing . 5

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_0476411 – 318Missing in isoform 3. 1 PublicationAdd BLAST318
Alternative sequenceiVSP_0394611 – 310Missing in isoform 2. 2 PublicationsAdd BLAST310
Alternative sequenceiVSP_039462311 – 315WGLYS → MERPI in isoform 2. 2 Publications5

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF031815 mRNA Translation: AAC26099.1
AJ251016 mRNA Translation: CAB61331.1
AF438203 mRNA Translation: AAL40801.1
AF336797 Genomic DNA Translation: AAK15345.1
AY138900 mRNA Translation: AAN46636.1
AL390204 Genomic DNA No translation available.
AL606500 Genomic DNA No translation available.
AL954342 Genomic DNA No translation available.
CH471121 Genomic DNA Translation: EAW53180.1
CH471121 Genomic DNA Translation: EAW53182.1
BC042147 mRNA Translation: AAH42147.1
CCDSiCCDS1072.1 [Q9UGI6-2]
RefSeqiNP_001191016.1, NM_001204087.1
NP_002240.3, NM_002249.5
NP_740752.1, NM_170782.2 [Q9UGI6-2]
UniGeneiHs.490765

Genome annotation databases

EnsembliENST00000358505; ENSP00000351295; ENSG00000143603 [Q9UGI6-3]
ENST00000361147; ENSP00000354764; ENSG00000143603 [Q9UGI6-2]
GeneIDi3782
KEGGihsa:3782
UCSCiuc001ffo.4 human [Q9UGI6-1]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Similar proteinsi

Entry informationi

Entry nameiKCNN3_HUMAN
AccessioniPrimary (citable) accession number: Q9UGI6
Secondary accession number(s): B1ANX0
, O43517, Q86VF9, Q8WXG7
Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 16, 2001
Last sequence update: May 1, 2000
Last modified: May 23, 2018
This is version 150 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny 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.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

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