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A8MYU2 (KCNU1_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Last modified April 16, 2014. Version 65. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (6) | 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
KCa5
Slowpoke homolog 3
Gene names
Name:KCNU1
Synonyms:KCNMA3, KCNMC1, SLO3
OrganismHomo sapiens (Human) [Reference proteome]
Taxonomic identifier9606 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo

Protein attributes

Sequence length1149 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+. May represent 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.3

Subunit structure

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

Subcellular location

Cell membrane; Multi-pass membrane protein By similarity.

Tissue specificity

Testis-specific. Ref.2

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 By similarity.

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 – 11491149Potassium channel subfamily U member 1
PRO_0000349186

Regions

Topological domain1 – 2424Extracellular Potential
Transmembrane25 – 4521Helical; Name=Segment S0; Potential
Topological domain46 – 10156Cytoplasmic Potential
Transmembrane102 – 12221Helical; Name=Segment S1; Potential
Topological domain123 – 13816Extracellular Potential
Transmembrane139 – 15921Helical; Name=Segment S2; Potential
Topological domain160 – 1634Cytoplasmic Potential
Transmembrane164 – 18421Helical; Name=Segment S3; Potential
Topological domain185 – 1884Extracellular 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 – 2919Extracellular Potential
Transmembrane292 – 31221Helical; Name=Segment S6; Potential
Topological domain313 – 1149837Cytoplasmic Potential
Domain339 – 482144RCK N-terminal
Region480 – 50021Segment S7
Region537 – 55721Segment S8
Region711 – 73121Segment S9
Region895 – 91521Segment S10
Motif276 – 2794Selectivity for potassium

Natural variations

Natural variant1751D → N.
Corresponds to variant rs1111125 [ dbSNP | Ensembl ].
VAR_060148
Natural variant7681W → R.
Corresponds to variant rs28608091 [ dbSNP | Ensembl ].
VAR_053868
Natural variant9161N → S.
Corresponds to variant rs16885577 [ dbSNP | Ensembl ].
VAR_053869

Secondary structure

........................................................................................................ 1149
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
A8MYU2 [UniParc].

Last modified September 2, 2008. Version 2.
Checksum: BA527F41498B6AA7

FASTA1,149129,543
        10         20         30         40         50         60 
MFQTKLRNET WEDLPKMSCT TEIQAAFILS SFVTFFSGLI ILLIFRLIWR SVKKWQIIKG 

        70         80         90        100        110        120 
TGIILELFTS GTIARSHVRS LHFQGQFRDH IEMLLSAQTF VGQVLVILVF VLSIGSLIIY 

       130        140        150        160        170        180 
FINSADPVGS CSSYEDKTIP IDLVFNAFFS FYFGLRFMAA DDKIKFWLEM NSIVDIFTIP 

       190        200        210        220        230        240 
PTFISYYLKS NWLGLRFLRA LRLLELPQIL QILRAIKTSN SVKFSKLLSI ILSTWFTAAG 

       250        260        270        280        290        300 
FIHLVENSGD PWLKGRNSQN ISYFESIYLV MATTSTVGFG DVVAKTSLGR TFIMFFTLGS 

       310        320        330        340        350        360 
LILFANYIPE MVELFANKRK YTSSYEALKG KKFIVVCGNI TVDSVTAFLR NFLRDKSGEI 

       370        380        390        400        410        420 
NTEIVFLGET PPSLELETIF KCYLAYTTFI SGSAMKWEDL RRVAVESAEA CLIIANPLCS 

       430        440        450        460        470        480 
DSHAEDISNI MRVLSIKNYD STTRIIIQIL QSHNKVYLPK IPSWNWDTGD NIICFAELKL 

       490        500        510        520        530        540 
GFIAQGCLVP GLCTFLTSLF VEQNKKVMPK QTWKKHFLNS MKNKILTQRL SDDFAGMSFP 

       550        560        570        580        590        600 
EVARLCFLKM HLLLIAIEYK SLFTDGFCGL ILNPPPQVRI RKNTLGFFIA ETPKDVRRAL 

       610        620        630        640        650        660 
FYCSVCHDDV FIPELITNCG CKSRSRQHIT VPSVKRMKKC LKGISSRISG QDSPPRVSAS 

       670        680        690        700        710        720 
TSSISNFTTR TLQHDVEQDS DQLDSSGMFH WCKPTSLDKV TLKRTGKSKY KFRNHIVACV 

       730        740        750        760        770        780 
FGDAHSAPMG LRNFVMPLRA SNYTRKELKD IVFIGSLDYL QREWRFLWNF PQIYILPGCA 

       790        800        810        820        830        840 
LYSGDLHAAN IEQCSMCAVL SPPPQPSSNQ TLVDTEAIMA TLTIGSLQID SSSDPSPSVS 

       850        860        870        880        890        900 
EETPGYTNGH NEKSNCRKVP ILTELKNPSN IHFIEQLGGL EGSLQETNLH LSTAFSTGTV 

       910        920        930        940        950        960 
FSGSFLDSLL ATAFYNYHVL ELLQMLVTGG VSSQLEQHLD KDKVYGVADS CTSLLSGRNR 

       970        980        990       1000       1010       1020 
CKLGLLSLHE TILSDVNPRN TFGQLFCGSL DLFGILCVGL YRIIDEEELN PENKRFVITR 

      1030       1040       1050       1060       1070       1080 
PANEFKLLPS DLVFCAIPFS TACYKRNEEF SLQKSYEIVN KASQTTETHS DTNCPPTIDS 

      1090       1100       1110       1120       1130       1140 
VTETLYSPVY SYQPRTNSLS FPKQIAWNQS RTNSIISSQI PLGDNAKENE RKTSDEVYDE 


DPFAYSEPL 

« Hide

References

« Hide 'large scale' references
[1]"DNA sequence and analysis of human chromosome 8."
Nusbaum C., Mikkelsen T.S., Zody M.C., Asakawa S., Taudien S., Garber M., Kodira C.D., Schueler M.G., Shimizu A., Whittaker C.A., Chang J.L., Cuomo C.A., Dewar K., FitzGerald M.G., Yang X., Allen N.R., Anderson S., Asakawa T. expand/collapse author list , Blechschmidt K., Bloom T., Borowsky M.L., Butler J., Cook A., Corum B., DeArellano K., DeCaprio D., Dooley K.T., Dorris L. III, Engels R., Gloeckner G., Hafez N., Hagopian D.S., Hall J.L., Ishikawa S.K., Jaffe D.B., Kamat A., Kudoh J., Lehmann R., Lokitsang T., Macdonald P., Major J.E., Matthews C.D., Mauceli E., Menzel U., Mihalev A.H., Minoshima S., Murayama Y., Naylor J.W., Nicol R., Nguyen C., O'Leary S.B., O'Neill K., Parker S.C.J., Polley A., Raymond C.K., Reichwald K., Rodriguez J., Sasaki T., Schilhabel M., Siddiqui R., Smith C.L., Sneddon T.P., Talamas J.A., Tenzin P., Topham K., Venkataraman V., Wen G., Yamazaki S., Young S.K., Zeng Q., Zimmer A.R., Rosenthal A., Birren B.W., Platzer M., Shimizu N., Lander E.S.
Nature 439:331-335(2006) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[2]"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: TISSUE SPECIFICITY.
[3]"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: X-RAY CRYSTALLOGRAPHY (3.4 ANGSTROMS) OF 330-1063, FUNCTION, PH DEPENDENCE.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AC124076 Genomic DNA. No translation available.
RefSeqNP_001027006.2. NM_001031836.2.
UniGeneHs.13861.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
4HPFX-ray3.40A/B330-1063[»]
ProteinModelPortalA8MYU2.
SMRA8MYU2. Positions 104-315, 331-1043.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

DIPDIP-60091N.
STRING9606.ENSP00000382770.

Chemistry

GuidetoPHARMACOLOGY387.

PTM databases

PhosphoSiteA8MYU2.

Proteomic databases

PaxDbA8MYU2.
PRIDEA8MYU2.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblENST00000399881; ENSP00000382770; ENSG00000215262.
GeneID157855.
KEGGhsa:157855.
UCSCuc010lvw.3. human.

Organism-specific databases

CTD157855.
GeneCardsGC08P036641.
H-InvDBHIX0020845.
HGNCHGNC:18867. KCNU1.
MIM615215. gene.
neXtProtNX_A8MYU2.
PharmGKBPA38727.
GenAtlasSearch...

Phylogenomic databases

eggNOGNOG253173.
HOGENOMHOG000019856.
HOVERGENHBG052222.
KOK05274.
OMASGMFHWC.
OrthoDBEOG7288R0.
PhylomeDBA8MYU2.
TreeFamTF314283.

Enzyme and pathway databases

ReactomeREACT_163848. Reproduction.

Gene expression databases

ArrayExpressA8MYU2.
BgeeA8MYU2.
CleanExHS_KCNU1.
GenevestigatorA8MYU2.

Family and domain databases

Gene3D3.40.50.720. 1 hit.
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

GeneWikiKCNU1.
GenomeRNAi157855.
NextBio87566.
PROA8MYU2.
SOURCESearch...

Entry information

Entry nameKCNU1_HUMAN
AccessionPrimary (citable) accession number: A8MYU2
Entry history
Integrated into UniProtKB/Swiss-Prot: September 2, 2008
Last sequence update: September 2, 2008
Last modified: April 16, 2014
This is version 65 of the entry and version 2 of the sequence. [Complete history]
Entry statusReviewed (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.

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

MIM cross-references

Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot

Human polymorphisms and disease mutations

Index of human polymorphisms and disease mutations

Human entries with polymorphisms or disease mutations

List of human entries with polymorphisms or disease mutations

Human chromosome 8

Human chromosome 8: entries, gene names and cross-references to MIM