UniProt:P55087 AQP4

chain
  • chain:1-323
checksum 1A1600CF0DC11052
comment
  • FUNCTION Forms a water-specific channel (PubMed:19383790, PubMed:7559426, PubMed:8601457). Plays an important role in brain water homeostasis (PubMed:37143309). It is involved in glymphatic solute transport and is required for a normal rate of water exchange across the blood brain interface. Required for normal levels of cerebrospinal fluid influx into the brain cortex and parenchyma along paravascular spaces that surround penetrating arteries, and for normal drainage of interstitial fluid along paravenous drainage pathways. Thereby, it is required for normal clearance of solutes from the brain interstitial fluid, including soluble beta-amyloid peptides derived from APP. Plays a redundant role in urinary water homeostasis and urinary concentrating ability (By similarity).CATALYTIC ACTIVITY H2O(in) = H2O(out)SUBUNIT Homotetramer (PubMed:19383790). The tetramers can form oligomeric arrays in membranes. The size of the oligomers differs between tissues and is smaller in skeletal muscle than in brain. Interaction between AQP4 oligomeric arrays in close-by cells can contribute to cell-cell adhesion (By similarity). Part of a complex containing MLC1, TRPV4, HEPACAM and ATP1B1 (PubMed:22328087).INTERACTION Activation of the vasopressin receptor AVPR1A triggers AQP4 phosphorylation at Ser-180 and promotes its internalization from the cell membrane. Detected on brain astrocyte processes and astrocyte endfeet close to capillaries.ALTERNATIVE PRODUCTS Detected in skeletal muscle (PubMed:29055082). Detected in stomach, along the glandular base region of the fundic gland (at protein level) (PubMed:8601457). Detected in brain, lung and skeletal muscle, and at much lower levels in heart and ovary (PubMed:7559426, PubMed:8601457).DOMAIN Aquaporins contain two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA).PTM Phosphorylation by PKC at Ser-180 reduces conductance by 50%. Phosphorylation by PKG at Ser-111 in response to glutamate increases conductance by 40% (By similarity).PTM Isoform 2: Palmitoylated on its N-terminal region. Isoform 1: Not palmitoylated.DISEASE The disease may be caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the MIP/aquaporin (TC 1.A.8) family.SEQUENCE CAUTION Extended N-terminus.
crossReference
databaseName UniProt
dbId 50182
description
  • recommendedName: Aquaporin-4 shortName: AQP-4 alternativeName: fullName evidence="11"Mercurial-insensitive water channel shortName evidence="11"MIWC alternativeName: WCH4
displayName UniProt:P55087 AQP4
geneName
  • AQP4
identifier P55087
isSequenceChanged false
keyword
  • 3D-structure
  • Alternative splicing
  • Cell membrane
  • Cell projection
  • Disease variant
  • Endosome
  • Glycoprotein
  • Lipoprotein
  • Membrane
  • Palmitate
  • Phosphoprotein
  • Proteomics identification
  • Reference proteome
  • Repeat
  • Transmembrane
  • Transmembrane helix
  • Transport
modified [InstanceEdit:9926675] Weiser, Joel, 2024-11-03
moleculeType Protein
name
  • AQP4
otherIdentifier
  • 11722619_a_at
  • 11722620_a_at
  • 11722621_a_at
  • 11752685_a_at
  • 11752686_x_at
  • 16854414
  • 210066_PM_s_at
  • 210066_s_at
  • 210067_PM_at
  • 210067_at
  • 210068_PM_s_at
  • 210068_s_at
  • 210906_PM_x_at
  • 210906_x_at
  • 226228_PM_at
  • 226228_at
  • 361
  • 3802398
  • 3802399
  • 3802400
  • 3802401
  • 3802402
  • 3802403
  • 3802404
  • 3802405
  • 3802406
  • 3802407
  • 3802408
  • 3802409
  • 3802410
  • 3802411
  • 3802412
  • 3802414
  • 3802415
  • 40793_s_at
  • 8022655
  • A_23_P107565
  • A_24_P202522
  • A_33_P3420757
  • D63412_at
  • GE57270
  • GE596123
  • GO:0003014
  • GO:0003091
  • GO:0005515
  • GO:0005576
  • GO:0005737
  • GO:0005768
  • GO:0005886
  • GO:0006833
  • GO:0007018
  • GO:0009897
  • GO:0009992
  • GO:0010008
  • GO:0015250
  • GO:0015267
  • GO:0016020
  • GO:0016323
  • GO:0042383
  • GO:0042802
  • GO:0042995
  • GO:0050877
  • GO:0050891
  • GO:0051289
  • GO:0055085
  • GO:0065003
  • GO:0071346
  • GO:0090660
  • GO:0097450
  • HMNXSV003003919
  • Hs.315369.0.S1_3p_at
  • ILMN_1676649
  • ILMN_1747683
  • PH_hs_0032638
  • TC18000429.hg
  • U34844_at
  • g1072054_3p_a_at
  • g1236245_3p_at
  • g1680707_3p_a_at
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • AQP4_HUMAN
  • P78564
sequenceLength 323
species [Species:48887] Homo sapiens
stId uniprot:P55087
url http://purl.uniprot.org/uniprot/P55087
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