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Protein

Potassium channel subfamily U member 1

Gene

Kcnu1

Organism
Mus musculus (Mouse)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

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.8 Publications

GO - Molecular functioni

  1. large conductance calcium-activated potassium channel activity Source: GO_Central
  2. voltage-gated potassium channel activity Source: GO_Central

GO - Biological processi

  1. potassium ion transmembrane transport Source: GO_Central
Complete GO annotation...

Keywords - Molecular functioni

Ion channel, Potassium channel, Voltage-gated channel

Keywords - Biological processi

Ion transport, Potassium transport, Transport

Keywords - Ligandi

Potassium

Protein family/group databases

TCDBi1.A.1.3.5. the voltage-gated ion channel (vic) superfamily.

Names & Taxonomyi

Protein namesi
Recommended 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 namesi
Name:Kcnu1
Synonyms:Kcnma3, Ksper, Slo3
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus
ProteomesiUP000000589: Unplaced

Organism-specific databases

MGIiMGI:1202300. Kcnu1.

Subcellular locationi

Cell membrane 1 Publication; Multi-pass membrane protein 1 Publication

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini1 – 2424ExtracellularSequence AnalysisAdd
BLAST
Transmembranei25 – 4521Helical; Name=Segment S0Sequence AnalysisAdd
BLAST
Topological domaini46 – 10156CytoplasmicSequence AnalysisAdd
BLAST
Transmembranei102 – 12221Helical; Name=Segment S1Sequence AnalysisAdd
BLAST
Topological domaini123 – 13715ExtracellularSequence AnalysisAdd
BLAST
Transmembranei138 – 15821Helical; Name=Segment S2Sequence AnalysisAdd
BLAST
Topological domaini159 – 1657CytoplasmicSequence Analysis
Transmembranei166 – 18621Helical; Name=Segment S3Sequence AnalysisAdd
BLAST
Topological domaini187 – 1882ExtracellularSequence Analysis
Transmembranei189 – 20921Helical; Voltage-sensor; Name=Segment S4Sequence AnalysisAdd
BLAST
Topological domaini210 – 22617CytoplasmicSequence AnalysisAdd
BLAST
Transmembranei227 – 24721Helical; Name=Segment S5Sequence AnalysisAdd
BLAST
Topological domaini248 – 25912ExtracellularSequence AnalysisAdd
BLAST
Intramembranei260 – 28223Pore-forming; Name=P regionSequence AnalysisAdd
BLAST
Topological domaini283 – 2908ExtracellularSequence Analysis
Transmembranei291 – 31121Helical; Name=Segment S6Sequence AnalysisAdd
BLAST
Topological domaini312 – 1121810CytoplasmicSequence AnalysisAdd
BLAST

GO - Cellular componenti

  1. voltage-gated potassium channel complex Source: GO_Central
Complete GO annotation...

Keywords - Cellular componenti

Cell membrane, Membrane

Pathology & Biotechi

Disruption phenotypei

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.1 Publication

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi279 – 2791F → Y: Does not induce any change in single channel conductance or variance in open current levels. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 11211121Potassium channel subfamily U member 1PRO_0000349188Add
BLAST

Proteomic databases

PRIDEiO54982.

Expressioni

Tissue specificityi

Testis-specific. Mainly expressed in spermatocytes.2 Publications

Developmental stagei

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 P150.1 Publication

Gene expression databases

GenevestigatoriO54982.

Interactioni

Subunit structurei

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.

Protein-protein interaction databases

STRINGi10090.ENSMUSP00000096457.

Structurei

3D structure databases

ProteinModelPortaliO54982.
SMRiO54982. Positions 148-316, 331-600, 686-1048.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Domaini339 – 482144RCK N-terminalAdd
BLAST

Region

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Regioni480 – 50021Segment S7Add
BLAST
Regioni537 – 55721Segment S8Add
BLAST
Regioni716 – 73621Segment S9Add
BLAST
Regioni900 – 92021Segment S1Add
BLAST

Motif

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Motifi276 – 2794Selectivity for potassium

Domaini

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).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.

Sequence similaritiesi

Contains 1 RCK N-terminal domain.Curated

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiNOG253173.
HOGENOMiHOG000019856.
HOVERGENiHBG052222.
InParanoidiO54982.
KOiK05274.
PhylomeDBiO54982.

Family and domain databases

Gene3Di3.40.50.720. 2 hits.
InterProiIPR005821. Ion_trans_dom.
IPR003929. K_chnl_Ca-activ_BK_asu.
IPR016040. NAD(P)-bd_dom.
[Graphical view]
PfamiPF03493. BK_channel_a. 1 hit.
PF00520. Ion_trans. 1 hit.
[Graphical view]
PRINTSiPR01449. BKCHANNELA.

Sequencei

Sequence statusi: Complete.

O54982-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSQTLLDSLN QKELTETSCT IEIQAAFILS SLATFFGGLI ILFLFRIALK
60 70 80 90 100
SSRSWKYVKG PRGLLELFSS RRIEANPLRK LYFHGVFRQR IEMLLSAQTV
110 120 130 140 150
VGQVLVILVF VLSIGSLVIY FINSMDPVRR CSSYEDKIVH GDLSFNAFFS
160 170 180 190 200
FYFGLRFWAA EDKIKFWLEM NSIVDIFTIP PTFISYYLKS NWLGLRFLRA
210 220 230 240 250
LRLLELPKIL QILQVIKTSN SVKLSKLLSI VISTWFTAAG FLHLVENSGD
260 270 280 290 300
PWLNGRNSQT MSYFESIYLV TATMSTVGFG DVVAKTSLGR IFIVFFTLGS
310 320 330 340 350
LILFANYIPE MVELFSTRKK YTKPYEAVKG KKFIVVCGNI TVDSVTAFLR
360 370 380 390 400
NFLHWKSGEI NIEIVFLGET LPCLELETLL KCHTSCTNFV CGTALKFEDL
410 420 430 440 450
KRVAVENSEA CLILANHFCS DLHDEDNSNI MRVLSIKNYY PQTRVIIQIL
460 470 480 490 500
QSQNKVFLSK IPNWDWSAGD NILCFAELKL GFIAQGCLVP GLCTFLTTLF
510 520 530 540 550
IEQNQKVFPK HPWQKHFLNG LKNKILTQRL SNDFVGMTFP QVSRLCFVKL
560 570 580 590 600
NLMLIAIQHK PFFHSCCTLI LNPSSQVRLN KDTLGFFIAD SSKAVKRAFF
610 620 630 640 650
YCSNCHSDVC NPELIGKCNC KIKSRQQLIA PTIMVMKSSL TDFTTSSHIH
660 670 680 690 700
ASMSTEIHTC FSREQPSLIT ITTNRPTTND TVDDTDMLDS SGMFHWCRAM
710 720 730 740 750
PLDKVVLKRS EKAKHEFQNH IVVCVFGDAQ CTLVGLRNFV MPLRASNYTR
760 770 780 790 800
QELKDIVFIG SLEYFQREWR FLRNFPKIHI MPGSALYMGD LIAVNVEQCS
810 820 830 840 850
MCVILATPYK ALSSQILVDT EAIMATLNIQ SLRITSPTPG SSKSEVKPSS
860 870 880 890 900
AFDSKERKQR YKQIPILTEL KNPSNIHFIE QMGGLDGMLK GTSLHLSTSF
910 920 930 940 950
STGAVFSDTF LDSLLATSFY NYHVVELLQM LVTGGISSEM EHYLVKEKPY
960 970 980 990 1000
KTTDDYEAIK SGRTRCKLGL LSLDQTVLSG INPRKTFGQL FCGSLDNFGI
1010 1020 1030 1040 1050
LCVGLYRMID EEEPSQEHKR FVITRPSNEC HLLPSDLVFC AIPFNTTCGK
1060 1070 1080 1090 1100
SDSSPSIQAQ NNSTNATTPL AQGSNFFDSH HADESHDLYP VDDTGERWSQ
1110 1120
HHHSRVYPLD TLDASDIVQE K
Length:1,121
Mass (Da):126,870
Last modified:March 7, 2006 - v2
Checksum:i4D7E0425B97B47A1
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF039213 mRNA. Translation: AAB99742.2.
CCDSiCCDS52530.1.
PIRiT42383.
RefSeqiNP_032458.3. NM_008432.3.
UniGeneiMm.289679.

Genome annotation databases

GeneIDi16532.
KEGGimmu:16532.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AF039213 mRNA. Translation: AAB99742.2.
CCDSiCCDS52530.1.
PIRiT42383.
RefSeqiNP_032458.3. NM_008432.3.
UniGeneiMm.289679.

3D structure databases

ProteinModelPortaliO54982.
SMRiO54982. Positions 148-316, 331-600, 686-1048.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

STRINGi10090.ENSMUSP00000096457.

Chemistry

GuidetoPHARMACOLOGYi387.

Protein family/group databases

TCDBi1.A.1.3.5. the voltage-gated ion channel (vic) superfamily.

Proteomic databases

PRIDEiO54982.

Protocols and materials databases

DNASUi16532.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

GeneIDi16532.
KEGGimmu:16532.

Organism-specific databases

CTDi157855.
MGIiMGI:1202300. Kcnu1.

Phylogenomic databases

eggNOGiNOG253173.
HOGENOMiHOG000019856.
HOVERGENiHBG052222.
InParanoidiO54982.
KOiK05274.
PhylomeDBiO54982.

Miscellaneous databases

NextBioi289949.
PROiO54982.
SOURCEiSearch...

Gene expression databases

GenevestigatoriO54982.

Family and domain databases

Gene3Di3.40.50.720. 2 hits.
InterProiIPR005821. Ion_trans_dom.
IPR003929. K_chnl_Ca-activ_BK_asu.
IPR016040. NAD(P)-bd_dom.
[Graphical view]
PfamiPF03493. BK_channel_a. 1 hit.
PF00520. Ion_trans. 1 hit.
[Graphical view]
PRINTSiPR01449. BKCHANNELA.
ProtoNetiSearch...

Publicationsi

  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.

Entry informationi

Entry nameiKCNU1_MOUSE
AccessioniPrimary (citable) accession number: O54982
Entry historyi
Integrated into UniProtKB/Swiss-Prot: September 2, 2008
Last sequence update: March 7, 2006
Last modified: February 4, 2015
This is version 109 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. MGD cross-references
    Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot
  2. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.