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O54982 (KCNU1_MOUSE) Reviewed, UniProtKB/Swiss-Prot

Last modified July 9, 2014. Version 106. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Potassium channel subfamily U member 1
Alternative name(s):
Calcium-activated potassium channel subunit alpha-3
Calcium-activated potassium channel, subfamily M subunit alpha-3
Pore-forming subunit of the sperm-specific alkalization activated K(+) current
Short name=KSper
Slowpoke homolog 3
Short name=mSlo3
pH-sensitive maxi potassium channel
Gene names
Name:Kcnu1
Synonyms:Kcnma3, Ksper, Slo3
OrganismMus musculus (Mouse) [Reference proteome]
Taxonomic identifier10090 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus

Protein attributes

Sequence length1121 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Testis-specific potassium channel activated by both intracellular pH and membrane voltage that mediates export of K+. Represents the primary spermatozoan K+ current. In contrast to KCNMA1/SLO1, it is not activated by Ca2+ or Mg2+. Critical for fertility. May play an important role in sperm osmoregulation required for the acquisition of normal morphology and motility when faced with osmotic challenges, such as those experienced after mixing with seminal fluid and entry into the vagina. Ref.1 Ref.2 Ref.3 Ref.4 Ref.5 Ref.6 Ref.7 Ref.9

Subunit structure

Homotetramer; which constitutes the calcium-activated potassium channel. May interact with LRRC52; this interaction may change some channel gating properties, such as shifting gating to more negative potentials at a given pH.

Subcellular location

Cell membrane; Multi-pass membrane protein Ref.8.

Tissue specificity

Testis-specific. Mainly expressed in spermatocytes. Ref.1 Ref.7

Developmental stage

Very low expression levels in testis before postnatal day 25 (P25). Levels strongly increase between P25 and P30, and then remain high from P30 through P150. Ref.8

Domain

The S4 segment, which is characterized by a series of positively charged amino acids at every third position, is part of the voltage-sensor By similarity.

The pore-forming domain (also referred as P region) is imbedded into the membrane, and forms the selectivity filter of the pore. It contains the signature sequence of potassium channels that displays selectivity to potassium By similarity.

The RCK N-terminal domain mediates the homotetramerization, thereby promoting the assembly of monomers into functional potassium channel By similarity.

The C-terminal cytosolic region confers the pH-dependence.

Disruption phenotype

Mutant males are infertile, but their sperm retains some fertility within in vitro fertilization assays. Spermatozoa exhibit a higher incidence of morphological abnormalities as compared to wild-type, accentuated by hypotonic challenge and deficits in motility, in the absence of bicarbonate. Ref.7

Sequence similarities

Belongs to the potassium channel family. Calcium-activated (TC 1.A.1.3) subfamily. KCa5.1/KCNU1 sub-subfamily. [View classification]

Contains 1 RCK N-terminal domain.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 11211121Potassium channel subfamily U member 1
PRO_0000349188

Regions

Topological domain1 – 2424Extracellular Potential
Transmembrane25 – 4521Helical; Name=Segment S0; Potential
Topological domain46 – 10156Cytoplasmic Potential
Transmembrane102 – 12221Helical; Name=Segment S1; Potential
Topological domain123 – 13715Extracellular Potential
Transmembrane138 – 15821Helical; Name=Segment S2; Potential
Topological domain159 – 1657Cytoplasmic Potential
Transmembrane166 – 18621Helical; Name=Segment S3; Potential
Topological domain187 – 1882Extracellular Potential
Transmembrane189 – 20921Helical; Voltage-sensor; Name=Segment S4; Potential
Topological domain210 – 22617Cytoplasmic Potential
Transmembrane227 – 24721Helical; Name=Segment S5; Potential
Topological domain248 – 25912Extracellular Potential
Intramembrane260 – 28223Pore-forming; Name=P region; Potential
Topological domain283 – 2908Extracellular Potential
Transmembrane291 – 31121Helical; Name=Segment S6; Potential
Topological domain312 – 1121810Cytoplasmic Potential
Domain339 – 482144RCK N-terminal
Region480 – 50021Segment S7
Region537 – 55721Segment S8
Region716 – 73621Segment S9
Region900 – 92021Segment S1
Motif276 – 2794Selectivity for potassium

Experimental info

Mutagenesis2791F → Y: Does not induce any change in single channel conductance or variance in open current levels. Ref.6

Sequences

Sequence LengthMass (Da)Tools
O54982 [UniParc].

Last modified March 7, 2006. Version 2.
Checksum: 4D7E0425B97B47A1

FASTA1,121126,870
        10         20         30         40         50         60 
MSQTLLDSLN QKELTETSCT IEIQAAFILS SLATFFGGLI ILFLFRIALK SSRSWKYVKG 

        70         80         90        100        110        120 
PRGLLELFSS RRIEANPLRK LYFHGVFRQR IEMLLSAQTV VGQVLVILVF VLSIGSLVIY 

       130        140        150        160        170        180 
FINSMDPVRR CSSYEDKIVH GDLSFNAFFS FYFGLRFWAA EDKIKFWLEM NSIVDIFTIP 

       190        200        210        220        230        240 
PTFISYYLKS NWLGLRFLRA LRLLELPKIL QILQVIKTSN SVKLSKLLSI VISTWFTAAG 

       250        260        270        280        290        300 
FLHLVENSGD PWLNGRNSQT MSYFESIYLV TATMSTVGFG DVVAKTSLGR IFIVFFTLGS 

       310        320        330        340        350        360 
LILFANYIPE MVELFSTRKK YTKPYEAVKG KKFIVVCGNI TVDSVTAFLR NFLHWKSGEI 

       370        380        390        400        410        420 
NIEIVFLGET LPCLELETLL KCHTSCTNFV CGTALKFEDL KRVAVENSEA CLILANHFCS 

       430        440        450        460        470        480 
DLHDEDNSNI MRVLSIKNYY PQTRVIIQIL QSQNKVFLSK IPNWDWSAGD NILCFAELKL 

       490        500        510        520        530        540 
GFIAQGCLVP GLCTFLTTLF IEQNQKVFPK HPWQKHFLNG LKNKILTQRL SNDFVGMTFP 

       550        560        570        580        590        600 
QVSRLCFVKL NLMLIAIQHK PFFHSCCTLI LNPSSQVRLN KDTLGFFIAD SSKAVKRAFF 

       610        620        630        640        650        660 
YCSNCHSDVC NPELIGKCNC KIKSRQQLIA PTIMVMKSSL TDFTTSSHIH ASMSTEIHTC 

       670        680        690        700        710        720 
FSREQPSLIT ITTNRPTTND TVDDTDMLDS SGMFHWCRAM PLDKVVLKRS EKAKHEFQNH 

       730        740        750        760        770        780 
IVVCVFGDAQ CTLVGLRNFV MPLRASNYTR QELKDIVFIG SLEYFQREWR FLRNFPKIHI 

       790        800        810        820        830        840 
MPGSALYMGD LIAVNVEQCS MCVILATPYK ALSSQILVDT EAIMATLNIQ SLRITSPTPG 

       850        860        870        880        890        900 
SSKSEVKPSS AFDSKERKQR YKQIPILTEL KNPSNIHFIE QMGGLDGMLK GTSLHLSTSF 

       910        920        930        940        950        960 
STGAVFSDTF LDSLLATSFY NYHVVELLQM LVTGGISSEM EHYLVKEKPY KTTDDYEAIK 

       970        980        990       1000       1010       1020 
SGRTRCKLGL LSLDQTVLSG INPRKTFGQL FCGSLDNFGI LCVGLYRMID EEEPSQEHKR 

      1030       1040       1050       1060       1070       1080 
FVITRPSNEC HLLPSDLVFC AIPFNTTCGK SDSSPSIQAQ NNSTNATTPL AQGSNFFDSH 

      1090       1100       1110       1120 
HADESHDLYP VDDTGERWSQ HHHSRVYPLD TLDASDIVQE K 

« Hide

References

[1]"Slo3, a novel pH-sensitive K+ channel from mammalian spermatocytes."
Schreiber M., Wei A., Yuan A., Gaut J., Saito M., Salkoff L.
J. Biol. Chem. 273:3509-3516(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], FUNCTION, TISSUE SPECIFICITY.
[2]"Intracellular Mg(2+) enhances the function of BK-type Ca(2+)-activated K(+) channels."
Shi J., Cui J.
J. Gen. Physiol. 118:589-606(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[3]"Gating and conductance properties of BK channels are modulated by the S9-S10 tail domain of the alpha subunit. A study of mSlo1 and mSlo3 wild-type and chimeric channels."
Moss B.L., Magleby K.L.
J. Gen. Physiol. 118:711-734(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[4]"Ligand-dependent activation of Slo family channels is defined by interchangeable cytosolic domains."
Xia X.-M., Zhang X., Lingle C.J.
J. Neurosci. 24:5585-5591(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[5]"Slo3 K+ channels: voltage and pH dependence of macroscopic currents."
Zhang X., Zeng X., Lingle C.J.
J. Gen. Physiol. 128:317-336(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[6]"pH-regulated Slo3 K+ channels: properties of unitary currents."
Zhang X., Zeng X., Xia X.-M., Lingle C.J.
J. Gen. Physiol. 128:301-315(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, MUTAGENESIS OF PHE-279.
[7]"Deletion of the Slo3 gene abolishes alkalization-activated K+ current in mouse spermatozoa."
Zeng X.H., Yang C., Kim S.T., Lingle C.J., Xia X.M.
Proc. Natl. Acad. Sci. U.S.A. 108:5879-5884(2011) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, IDENTIFICATION AS KSPER, DISRUPTION PHENOTYPE, TISSUE SPECIFICITY.
[8]"LRRC52 (leucine-rich-repeat-containing protein 52), a testis-specific auxiliary subunit of the alkalization-activated Slo3 channel."
Yang C., Zeng X.H., Zhou Y., Xia X.M., Lingle C.J.
Proc. Natl. Acad. Sci. U.S.A. 108:19419-19424(2011) [PubMed] [Europe PMC] [Abstract]
Cited for: INTERACTION WITH LRRC52, SUBCELLULAR LOCATION, DEVELOPMENTAL STAGE.
[9]"Functional and structural analysis of the human SLO3 pH- and voltage-gated K+ channel."
Leonetti M.D., Yuan P., Hsiung Y., Mackinnon R.
Proc. Natl. Acad. Sci. U.S.A. 109:19274-19279(2012) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, PH DEPENDENCE.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF039213 mRNA. Translation: AAB99742.2.
CCDSCCDS52530.1.
PIRT42383.
RefSeqNP_032458.3. NM_008432.3.
UniGeneMm.289679.

3D structure databases

ProteinModelPortalO54982.
SMRO54982. Positions 148-316, 331-600, 686-1048.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

STRING10090.ENSMUSP00000096457.

Chemistry

GuidetoPHARMACOLOGY387.

Protein family/group databases

TCDB1.A.1.3.5. the voltage-gated ion channel (vic) superfamily.

Proteomic databases

PRIDEO54982.

Protocols and materials databases

DNASU16532.
StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

GeneID16532.
KEGGmmu:16532.

Organism-specific databases

CTD157855.
MGIMGI:1202300. Kcnu1.

Phylogenomic databases

eggNOGNOG253173.
HOGENOMHOG000019856.
HOVERGENHBG052222.
InParanoidO54982.
KOK05274.
PhylomeDBO54982.

Gene expression databases

GenevestigatorO54982.

Family and domain databases

Gene3D3.40.50.720. 2 hits.
InterProIPR005821. Ion_trans_dom.
IPR003929. K_chnl_Ca-activ_BK_asu.
IPR016040. NAD(P)-bd_dom.
[Graphical view]
PfamPF03493. BK_channel_a. 1 hit.
PF00520. Ion_trans. 1 hit.
[Graphical view]
PRINTSPR01449. BKCHANNELA.
ProtoNetSearch...

Other

NextBio289949.
PROO54982.
SOURCESearch...

Entry information

Entry nameKCNU1_MOUSE
AccessionPrimary (citable) accession number: O54982
Entry history
Integrated into UniProtKB/Swiss-Prot: September 2, 2008
Last sequence update: March 7, 2006
Last modified: July 9, 2014
This is version 106 of the entry and version 2 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

MGD cross-references

Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot