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FLASH GENE
Symbol AQP2 contributors: mct/npt/pgu - updated : 02-04-2017
HGNC name aquaporin 2 (collecting duct)
HGNC id 634
Corresponding disease
DIR2 nephrogenic diabetes insipidus, autosomal
Location 12q13.12      Physical location : 50.344.523 - 50.352.662
Synonym name
  • aquaporin 2, water channel forming integral protein
  • collecting duct water channel protein
  • Synonym symbol(s) AQP-CD, MGC34501, WCH-CD
    DNA
    TYPE functioning gene
    STRUCTURE 8.14 kb     4 Exon(s)
    10 Kb 5' upstream gene genomic sequence study
    MAPPING cloned Y linked   status confirmed
    Map cen - D12S1997 - (PRPH ,D12S1627 ) - D12S1129E - AQP2 - D12S131 - GPD1 - D12S1425 - D12S1145E - D12S1249E - D12S1401 - D12S361 - D12S1811 - ELA1 - D12S1629 - D12S1951 - D12S1546 - D12S347 - (ACVRL1 ,ACVR1B ) - D12S1712 - D12S297 - D12S368 - KRT7 - D12S270 - qter
    Authors 4st Workshop chrom.12 (97)
    RNA
    TRANSCRIPTS type messenger
    identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    4 - 4222 - 271 - 2007 17636261
    EXPRESSION
    Type restricted
       expressed in (based on citations)
    organ(s)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Hearing/Equilibriumearinnercochlea   Homo sapiens
    Reproductivefemale systemuteruscervix  
     male systemprostate   
    Respiratoryrespiratory tracttrachea   
    Urinarykidneytubule  highly Homo sapiens
    Visualeye    
    tissue
    SystemTissueTissue level 1Tissue level 2LevelPubmedSpeciesStageRna symbol
    Epithelialsecretoryglandular  
    cells
    SystemCellPubmedSpeciesStageRna symbol
    Hearing / Equilibriumcochlea cell Homo sapiens
    Skin/Tegumentduct
    cell lineage
    cell lines
    fluid/secretion
    at STAGE
    PROTEIN
    PHYSICAL PROPERTIES
    STRUCTURE
    motifs/domains
  • six transmembrane domains connected by loops A and E with the N-and C-termini located intracellularly
  • two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA)
  • 71 AA C terminal tail including a putative PDZ-interacting motif (G-T-K-A, residues 268-271) wich plays a key role in apical membrane expression
  • mono polymer homomer , tetramer
    HOMOLOGY
    interspecies homolog to murine Aqp2
    Homologene
    FAMILY
  • MIP/aquaporin family
  • CATEGORY regulatory , transport channel
    SUBCELLULAR LOCALIZATION     plasma membrane
        intracellular
    intracellular,cytoplasm,organelle,membrane
    intracellular,cytoplasm,organelle,endoplasmic reticulum
    intracellular,cytoplasm,organelle,Golgi
    intracellular,cytoplasm,cytosolic,vesicle
    text
  • translocating from intracellular vesicles to the apical plasma membrane
  • integral membrane protein
  • translocation of AQP2 is initiated by an increase in cAMP following AVPR2 activation through AVP
  • basic FUNCTION
  • ‘‘orthodox’’aquaporin, that transport only water molecules
  • increasing water, predominantly in response to vasopressin (AVP)
  • playing an important role in fluid homeostasis of the inner ear
  • providing the plasma membrane of renal collecting duct with high permeability to water, thereby permitting water to move in the direction of an osmotic gradient
  • its phosphorylation regulates its endocytosis and protein-protein interactions (
  • its expression facilitates cell swelling or shrinkage leading to the activation of channels necessary to the control of initiation of cell proliferation or apoptosis
  • mediates E(2)-enhanced migration, invasion, and adhesion through alteration of F-actin and annexin-2 expression and reorganization of F-actin
  • CELLULAR PROCESS
    PHYSIOLOGICAL PROCESS
    text water channel
    PATHWAY
    metabolism
    signaling
    a component
    INTERACTION
    DNA
    RNA
    small molecule
    protein
  • direct binding to cytoskeletal protein actin (providing a novel mechanism for trafficking of not only AQP2 but also recycling channel proteins)
  • putative substrate of calcineurin phosphatase in the kidney
  • interacts with other players of the ESCRT machinery as well as with two known cargo proteins, AQP2 and EGFR, whose degradation is affected upon reduction of VTA1 expression
  • interacting with AVP (modulates the water channel aquaporin-2 (AQP2) in the renal collecting duct to maintain homeostasis of body water)
  • intreracting with TBC1D4 (decreased expression of TBC1D4 is likely to play a role in the translocation of AQP2 to the plasma membrane)
  • CUL5 is involved in the regulation of AQP2 protein concentration and may play a role in regulating water balance
  • NR1H4 plays a critical role in the regulation of urine volume, and its activation increases urinary concentrating capacity mainly via up-regulating its target gene AQP2 expression in the collecting ducts
  • GATA2 regulates the AQP2 gene expression in collecting duct (CD) cells and contributes to the maintenance of the body water homeostasis
  • ELF5 is a principal cell lineage specific transcription factor in the kidney that contributes to AQP2 and AVPR2 gene expression
  • interaction between the renal water channel aquaporin-2 (AQP2) and the lysosomal trafficking regulator-interacting protein VTA1 targets AQP2 to multivesicular bodies and facilitates lysosomal degradation
  • through direct interaction with AQP2, EZR facilitates AQP2 endocytosis, thus linking the dynamic actin cytoskeleton network with AQP2 trafficking
  • FXYD1 (phospholemman), better known as a regulator of Na,K-ATPase, has a role in AQP2 trafficking
  • cell & other
    REGULATION
    Phosphorylated by AVP (Vasopressin regulates phosphorylation of AQP2 at four conserved serine residues at the COOH-terminal tail (S256, S261, S264, and S269)
    ASSOCIATED DISORDERS
    corresponding disease(s) DIR2
    related resource Nephrotic diabetes Insipidus
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional     --over  
    in the endolymphatic sac was significantly in Meniere patients
    Susceptibility
  • to Ménière disease
  • Variant & Polymorphism SNP
  • variant rs426496 in AQP2 were found in patients with Ménière disease
  • Candidate gene
    Marker
    Therapy target
    SystemTypeDisorderPubmed
    neurosensorialear 
    aquaporins appear to be important for the development of novel drug therapies for Meniere disease and related disorders
    cancer  
    inhibition of AQP may be a potential method for antitumor therapy
    ANIMAL & CELL MODELS