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Protein

Amiloride-sensitive sodium channel subunit alpha

Gene

SCNN1A

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Sodium permeable non-voltage-sensitive ion channel inhibited by the diuretic amiloride. Mediates the electrodiffusion of the luminal sodium (and water, which follows osmotically) through the apical membrane of epithelial cells. Plays an essential role in electrolyte and blood pressure homeostasis, but also in airway surface liquid homeostasis, which is important for proper clearance of mucus. Controls the reabsorption of sodium in kidney, colon, lung and eccrine sweat glands. Also plays a role in taste perception.2 Publications

Enzyme regulationi

Activated by WNK1, WNK2, WNK3 and WNK4.By similarity

GO - Molecular functioni

  • ligand-gated sodium channel activity Source: InterPro
  • WW domain binding Source: BHF-UCL

GO - Biological processi

  • ion transmembrane transport Source: Reactome
  • multicellular organismal water homeostasis Source: UniProtKB
  • response to stimulus Source: UniProtKB-KW
  • sensory perception of taste Source: UniProtKB-KW
  • sodium ion homeostasis Source: UniProtKB
  • sodium ion transmembrane transport Source: UniProtKB

Keywordsi

Molecular functionIon channel, Sodium channel
Biological processIon transport, Sensory transduction, Sodium transport, Taste, Transport
LigandSodium

Enzyme and pathway databases

ReactomeiR-HSA-2672351. Stimuli-sensing channels.
SIGNORiP37088.

Protein family/group databases

TCDBi1.A.6.1.1. the epithelial na(+) channel (enac) family.

Names & Taxonomyi

Protein namesi
Recommended name:
Amiloride-sensitive sodium channel subunit alpha
Alternative name(s):
Alpha-NaCH
Epithelial Na(+) channel subunit alpha
Short name:
Alpha-ENaC
Short name:
ENaCA
Nonvoltage-gated sodium channel 1 subunit alpha
SCNEA
Gene namesi
Name:SCNN1A
Synonyms:SCNN1
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 12

Organism-specific databases

EuPathDBiHostDB:ENSG00000111319.12.
HGNCiHGNC:10599. SCNN1A.

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
Topological domaini1 – 85CytoplasmicBy similarityAdd BLAST85
Transmembranei86 – 106Helical; Name=1Sequence analysisAdd BLAST21
Topological domaini107 – 562ExtracellularBy similarityAdd BLAST456
Transmembranei563 – 583Helical; Name=2Sequence analysisAdd BLAST21
Topological domaini584 – 669CytoplasmicBy similarityAdd BLAST86

Keywords - Cellular componenti

Cell membrane, Cell projection, Cytoplasm, Membrane

Pathology & Biotechi

Involvement in diseasei

Pseudohypoaldosteronism 1, autosomal recessive (PHA1B)3 Publications
The disease is caused by mutations affecting the gene represented in this entry. The degree of channel function impairment differentially affects the renin-aldosterone system and urinary Na/K ratios, resulting in distinct genotype-phenotype relationships in PHA1 patients. Loss-of-function mutations are associated with a severe clinical course and age-dependent hyperactivation of the renin-aldosterone system. This feature is not observed in patients with missense mutations that reduce but do not eliminate channel function. Markedly reduced channel activity results in impaired linear growth and delayed puberty (PubMed:18634878).1 Publication
Disease descriptionA rare salt wasting disease resulting from target organ unresponsiveness to mineralocorticoids. PHA1B is a severe form involving multiple organ systems, and characterized by an often fulminant presentation in the neonatal period with dehydration, hyponatremia, hyperkalemia, metabolic acidosis, failure to thrive and weight loss.
See also OMIM:264350
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_026518327G → C in PHA1B; results in a significant reduction of channel function as compared to wild-type; significantly lowers both Li+ and Na+ ion currents. 2 Publications1
Natural variantiVAR_015834562S → L in PHA1B. 1 PublicationCorresponds to variant dbSNP:rs137852635Ensembl.1
Bronchiectasis with or without elevated sweat chloride 2 (BESC2)1 Publication
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA debilitating respiratory disease characterized by chronic, abnormal dilatation of the bronchi and other cystic fibrosis-like symptoms in the absence of known causes of bronchiectasis (cystic fibrosis, autoimmune diseases, ciliary dyskinesia, common variable immunodeficiency, foreign body obstruction). Clinical features include sub-normal lung function, sinopulmonary infections, chronic productive cough, excessive sputum production, and elevated sweat chloride in some cases.
See also OMIM:613021
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06079361F → L in BESC2; hypoactive mutation resulting in reduction of protein expression and a significant decrease of amiloride-sensitive sodium currents. 1 PublicationCorresponds to variant dbSNP:rs61758859Ensembl.1
Natural variantiVAR_060794114V → I in BESC2; hyperactive mutation resulting in a significant increase of amiloride-sensitive sodium currents. 1 PublicationCorresponds to variant dbSNP:rs61759861Ensembl.1
Natural variantiVAR_015833493W → R Functional polymorphism; results in a 4-fold increase of amiloride-sensitive sodium currents; found in BESC2 patients at higher frequency than in controls; associated with an increased risk for ischemic cerebrovascular events. 2 PublicationsCorresponds to variant dbSNP:rs5742912Ensembl.1

Keywords - Diseasei

Disease mutation

Organism-specific databases

DisGeNETi6337.
MalaCardsiSCNN1A.
MIMi264350. phenotype.
613021. phenotype.
OpenTargetsiENSG00000111319.
Orphaneti171876. Generalized pseudohypoaldosteronism type 1.
60033. Idiopathic bronchiectasis.
PharmGKBiPA305.

Chemistry databases

ChEMBLiCHEMBL1791.
DrugBankiDB00594. Amiloride.
DB00384. Triamterene.
GuidetoPHARMACOLOGYi738.

Polymorphism and mutation databases

BioMutaiSCNN1A.
DMDMi585966.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00001812611 – 669Amiloride-sensitive sodium channel subunit alphaAdd BLAST669

Post-translational modificationi

Ubiquitinated; this targets individual subunits for endocytosis and proteasome-mediated degradation.By similarity
ENaC cleavage by furin, and subsequently by prostasin (PRSS8), leads to a stepwise increase in the open probability of the channel as a result of release of the alpha and gamma subunit inhibitory tracts, respectively. Interaction of ENaC subunit SCNN1B with BPIFA1 protects ENaC against proteolytic activation.1 Publication
N-glycosylated.By similarity

Keywords - PTMi

Glycoprotein, Ubl conjugation

Proteomic databases

EPDiP37088.
PaxDbiP37088.
PeptideAtlasiP37088.
PRIDEiP37088.

PTM databases

iPTMnetiP37088.
PhosphoSitePlusiP37088.

Expressioni

Tissue specificityi

Expressed in the female reproductive tract, from the fimbrial end of the fallopian tube to the endometrium (at protein level) (PubMed:22207244). Expressed in kidney (at protein level). In the respiratory tract, expressed in the bronchial epithelium (at protein level). Highly expressed in lung. Detected at intermediate levels in pancreas and liver, and at low levels in heart and placenta (PubMed:22207244). in skin, expressed in keratinocytes, melanocytes and Merkel cells of the epidermal sub-layers, stratum basale, stratum spinosum and stratum granulosum (at protein level) (PubMed:28130590). Expressed in the outer root sheath of the hair follicles (at protein level) (PubMed:28130590). Detected in both peripheral and central cells of the sebaceous gland (at protein level) (PubMed:28130590). Expressed by eccrine sweat glands (at protein level) (PubMed:28130590). In skin, also expressed by arrector pili muscle cells and intradermal adipocytes (PubMed:28130590). Isoform 1 and isoform 2 predominate in all tissues. Expression of isoform 3, isoform 4 and isoform 5 is very low or not detectable, except in lung and heart (PubMed:9575806).3 Publications

Inductioni

By aldosterone.1 Publication

Gene expression databases

BgeeiENSG00000111319.
CleanExiHS_SCNN1A.
ExpressionAtlasiP37088. baseline and differential.
GenevisibleiP37088. HS.

Organism-specific databases

HPAiHPA012743.

Interactioni

Subunit structurei

Heterotrimer containing an alpha/SCNN1A, a beta/SCNN1B and a gamma/SCNN1G subunit. An additional delta/SCNN1D subunit exists only in some organisms and can replace the alpha/SCNN1A subunit to form an alternative channel with specific properties (By similarity). Interacts with NEDD4 (via WW domains) (PubMed:11244092, PubMed:11696533, PubMed:12167593, PubMed:23665454). Interacts with NEDD4L (via WW domains) (PubMed:11244092, PubMed:11696533). Interacts with WWP1 (via WW domains) (PubMed:9169421). Interacts with WWP2 (via WW domains) (PubMed:12167593, PubMed:9169421). Interacts with the full-length immature form of PCSK9 (pro-PCSK9) (PubMed:22493497).By similarity6 Publications

Binary interactionsi

Show more details

GO - Molecular functioni

  • WW domain binding Source: BHF-UCL

Protein-protein interaction databases

BioGridi112241. 23 interactors.
CORUMiP37088.
ELMiP37088.
IntActiP37088. 4 interactors.
MINTiMINT-198663.
STRINGi9606.ENSP00000353292.

Chemistry databases

BindingDBiP37088.

Structurei

Secondary structure

1669
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi644 – 647Combined sources4

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
2M3ONMR-P638-648[»]
ProteinModelPortaliP37088.
SMRiP37088.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG4294. Eukaryota.
ENOG410ZNFK. LUCA.
GeneTreeiENSGT00760000119120.
HOGENOMiHOG000236286.
HOVERGENiHBG058435.
InParanoidiP37088.
KOiK04824.
OMAiVEYCDYR.
OrthoDBiEOG091G0KW6.
PhylomeDBiP37088.
TreeFamiTF330663.

Family and domain databases

InterProiView protein in InterPro
IPR001873. ENaC.
IPR004724. ENaC_chordates.
IPR020903. ENaC_CS.
PANTHERiPTHR11690. PTHR11690. 1 hit.
PfamiView protein in Pfam
PF00858. ASC. 1 hit.
PRINTSiPR01078. AMINACHANNEL.
TIGRFAMsiTIGR00859. ENaC. 1 hit.
PROSITEiView protein in PROSITE
PS01206. ASC. 1 hit.

Sequences (6)i

Sequence statusi: Complete.

This entry describes 6 isoformsi produced by alternative splicing. AlignAdd to basket

Isoform 1 (identifier: P37088-1) [UniParc]FASTAAdd to basket
Also known as: Alpha ENAC1

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
MEGNKLEEQD SSPPQSTPGL MKGNKREEQG LGPEPAAPQQ PTAEEEALIE
60 70 80 90 100
FHRSYRELFE FFCNNTTIHG AIRLVCSQHN RMKTAFWAVL WLCTFGMMYW
110 120 130 140 150
QFGLLFGEYF SYPVSLNINL NSDKLVFPAV TICTLNPYRY PEIKEELEEL
160 170 180 190 200
DRITEQTLFD LYKYSSFTTL VAGSRSRRDL RGTLPHPLQR LRVPPPPHGA
210 220 230 240 250
RRARSVASSL RDNNPQVDWK DWKIGFQLCN QNKSDCFYQT YSSGVDAVRE
260 270 280 290 300
WYRFHYINIL SRLPETLPSL EEDTLGNFIF ACRFNQVSCN QANYSHFHHP
310 320 330 340 350
MYGNCYTFND KNNSNLWMSS MPGINNGLSL MLRAEQNDFI PLLSTVTGAR
360 370 380 390 400
VMVHGQDEPA FMDDGGFNLR PGVETSISMR KETLDRLGGD YGDCTKNGSD
410 420 430 440 450
VPVENLYPSK YTQQVCIHSC FQESMIKECG CAYIFYPRPQ NVEYCDYRKH
460 470 480 490 500
SSWGYCYYKL QVDFSSDHLG CFTKCRKPCS VTSYQLSAGY SRWPSVTSQE
510 520 530 540 550
WVFQMLSRQN NYTVNNKRNG VAKVNIFFKE LNYKTNSESP SVTMVTLLSN
560 570 580 590 600
LGSQWSLWFG SSVLSVVEMA ELVFDLLVIM FLMLLRRFRS RYWSPGRGGR
610 620 630 640 650
GAQEVASTLA SSPPSHFCPH PMSLSLSQPG PAPSPALTAP PPAYATLGPR
660
PSPGGSAGAS SSTCPLGGP
Length:669
Mass (Da):75,704
Last modified:October 1, 1994 - v1
Checksum:i2CCF342E7DF32E72
GO
Isoform 2 (identifier: P37088-2) [UniParc]FASTAAdd to basket
Also known as: Alpha ENAC2

The sequence of this isoform differs from the canonical sequence as follows:
     1-1: M → MGMARGSLTRVPGVMGEGTQGPELSLDPDPCSPQSTPGLMKGNKLEEQDPRPLQPIPGLM

Show »
Length:728
Mass (Da):81,856
Checksum:i206613374DFB1800
GO
Isoform 3 (identifier: P37088-3) [UniParc]FASTAAdd to basket
Also known as: Alpha ENACx

The sequence of this isoform differs from the canonical sequence as follows:
     229-245: CNQNKSDCFYQTYSSGV → ELLSLPPPDVWKLLYFG
     246-669: Missing.

Note: Does not give rise to amiloride-sensitive ion current. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.
Show »
Length:245
Mass (Da):28,328
Checksum:iFFDC0622FFA37329
GO
Isoform 4 (identifier: P37088-4) [UniParc]FASTAAdd to basket
Also known as: Alpha ENAC-19

The sequence of this isoform differs from the canonical sequence as follows:
     327-345: Missing.

Note: Amiloride-sensitive ion current is nearly abolished.
Show »
Length:650
Mass (Da):73,603
Checksum:i5866D42CCAF6F8B4
GO
Isoform 5 (identifier: P37088-5) [UniParc]FASTAAdd to basket
Also known as: Alpha ENAC+22

The sequence of this isoform differs from the canonical sequence as follows:
     454-454: G → GQVRSLTPVIPALWEAEAGGSRG

Note: Does not give rise to amiloride-sensitive ion current.
Show »
Length:691
Mass (Da):77,980
Checksum:i07B981FBE74AE30B
GO
Isoform 6 (identifier: P37088-6) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     1-1: M → MSSIKGNKLEEQDPRPLQPIPGLM

Note: No experimental confirmation available.
Show »
Length:692
Mass (Da):78,234
Checksum:i3AD7710E69D1BE54
GO

Sequence cautioni

The sequence AAH06526 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.Curated

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06079361F → L in BESC2; hypoactive mutation resulting in reduction of protein expression and a significant decrease of amiloride-sensitive sodium currents. 1 PublicationCorresponds to variant dbSNP:rs61758859Ensembl.1
Natural variantiVAR_060794114V → I in BESC2; hyperactive mutation resulting in a significant increase of amiloride-sensitive sodium currents. 1 PublicationCorresponds to variant dbSNP:rs61759861Ensembl.1
Natural variantiVAR_060795181R → W Functional polymorphism; significant increase of amiloride-sensitive sodium currents. 2 PublicationsCorresponds to variant dbSNP:rs55797039Ensembl.1
Natural variantiVAR_026518327G → C in PHA1B; results in a significant reduction of channel function as compared to wild-type; significantly lowers both Li+ and Na+ ion currents. 2 Publications1
Natural variantiVAR_060796334A → T Functional polymorphism; significant decrease of amiloride-sensitive sodium currents. 2 PublicationsCorresponds to variant dbSNP:rs11542844Ensembl.1
Natural variantiVAR_052035402P → H. Corresponds to variant dbSNP:rs13306616Ensembl.1
Natural variantiVAR_015833493W → R Functional polymorphism; results in a 4-fold increase of amiloride-sensitive sodium currents; found in BESC2 patients at higher frequency than in controls; associated with an increased risk for ischemic cerebrovascular events. 2 PublicationsCorresponds to variant dbSNP:rs5742912Ensembl.1
Natural variantiVAR_015834562S → L in PHA1B. 1 PublicationCorresponds to variant dbSNP:rs137852635Ensembl.1
Natural variantiVAR_060797573V → I. Corresponds to variant dbSNP:rs59142484Ensembl.1
Natural variantiVAR_022142618C → F1 PublicationCorresponds to variant dbSNP:rs3741913Ensembl.1
Natural variantiVAR_015835663T → A7 PublicationsCorresponds to variant dbSNP:rs2228576Ensembl.1

Alternative sequence

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Alternative sequenceiVSP_0077191M → MGMARGSLTRVPGVMGEGTQ GPELSLDPDPCSPQSTPGLM KGNKLEEQDPRPLQPIPGLM in isoform 2. Curated1
Alternative sequenceiVSP_0436671M → MSSIKGNKLEEQDPRPLQPI PGLM in isoform 6. 1 Publication1
Alternative sequenceiVSP_007720229 – 245CNQNK…YSSGV → ELLSLPPPDVWKLLYFG in isoform 3. CuratedAdd BLAST17
Alternative sequenceiVSP_007721246 – 669Missing in isoform 3. CuratedAdd BLAST424
Alternative sequenceiVSP_007722327 – 345Missing in isoform 4. CuratedAdd BLAST19
Alternative sequenceiVSP_007723454G → GQVRSLTPVIPALWEAEAGG SRG in isoform 5. Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
X76180 mRNA. Translation: CAA53773.1.
L29007 Genomic DNA. Translation: AAA21813.1.
Z92978
, Z92979, Z92980, Z92981 Genomic DNA. Translation: CAB07505.1.
AF060913
, AF060910, AF060911, AF060912 Genomic DNA. Translation: AAD28355.1.
DQ402522 mRNA. Translation: ABD72218.1.
AK304379 mRNA. Translation: BAG65217.1.
FJ515830 Genomic DNA. Translation: ACS13721.1.
AC005840 Genomic DNA. No translation available.
AC006057 Genomic DNA. No translation available.
CH471116 Genomic DNA. Translation: EAW88804.1.
BC006526 mRNA. Translation: AAH06526.2. Different initiation.
BC062613 mRNA. Translation: AAH62613.1.
U81961 Genomic DNA. Translation: AAC31773.1.
U81961 Genomic DNA. Translation: AAC31774.1.
CCDSiCCDS53738.1. [P37088-2]
CCDS53739.1. [P37088-6]
CCDS8543.1. [P37088-1]
PIRiA49585.
RefSeqiNP_001029.1. NM_001038.5. [P37088-1]
NP_001153047.1. NM_001159575.1. [P37088-6]
NP_001153048.1. NM_001159576.1. [P37088-2]
UniGeneiHs.591047.

Genome annotation databases

EnsembliENST00000228916; ENSP00000228916; ENSG00000111319. [P37088-1]
ENST00000360168; ENSP00000353292; ENSG00000111319. [P37088-2]
ENST00000543768; ENSP00000438739; ENSG00000111319. [P37088-6]
GeneIDi6337.
KEGGihsa:6337.
UCSCiuc001qnw.3. human. [P37088-1]

Keywords - Coding sequence diversityi

Alternative splicing, Polymorphism

Similar proteinsi

Entry informationi

Entry nameiSCNNA_HUMAN
AccessioniPrimary (citable) accession number: P37088
Secondary accession number(s): A5X2U9
, B4E2Q5, C5HTZ0, O43271, Q6GSQ6, Q9UM64
Entry historyiIntegrated into UniProtKB/Swiss-Prot: October 1, 1994
Last sequence update: October 1, 1994
Last modified: September 27, 2017
This is version 184 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

3D-structure, Complete proteome, Reference proteome

Documents

  1. Human chromosome 12
    Human chromosome 12: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. SIMILARITY comments
    Index of protein domains and families