aquaporin-3 aquaporin-3 aquaporin 3 (aqp-3) is the protein product of the human aqp3 gene. it is found in the basolateral cell membrane of principal collecting duct cells and provides a pathway for water to exit these cells. aquaporin-3 is also permeable to glycerol, ammonia, urea, and hydrogen peroxide. it is expressed in various tissues including the skin, respiratory tract, and kidneys as well as various types of cancers. in the kidney, aquaproin-3 is unresponsive to the antidiuretic hormone vasopressin, unlike aquaporin-2. this protein is also a determinant for the gil blood group system. aqp3identifiersaliasesaqp3, aqp-3, gil, aquaporin 3 (gill blood group)external idsomim: 600170 mgi: 1333777 homologene: 21025 genecards: aqp3 gene location (human)chr.chromosome 9 (human)band9p13.3start33,441,156 bpend33,447,596 bpgene location (mouse)chr.chromosome 4 (mouse)band4|4 a5start41,092,722 bpend41,098,183 bprna expression patternbgeehumanmouse (ortholog)top expressed inparotid glandhuman penispalpebral conjunctivavulvacavity of mouthnippletracheabronchusbronchial epithelial cellrenal medullatop expressed inlipolfactory epitheliumyolk sacesophagusmucous cell of stomachconjunctival fornixcorneapyloric antrumkidneymorulamore reference expression databiogpsn/agene ontologymolecular function water channel activity glycerol channel activity transporter activity channel activity urea transmembrane transporter activity cellular component cytoplasm integral component of membrane membrane cell-cell junction plasma membrane basolateral plasma membrane nucleus biological process positive regulation of immune system process excretion response to vitamin d response to retinoic acid water transport urea transport odontogenesis response to calcium ion renal water homeostasis regulation of keratinocyte differentiation renal water absorption glycerol transport cellular response to oxygen-glucose deprivation cellular response to hypoxia transmembrane transport urea transmembrane transport sources:amigo / quickgoorthologsspecieshumanmouseentrez36011828ensemblensg00000165272ensmusg00000028435uniprotq92482q8r2n1refseq (mrna)nm_004925nm_001318144nm_016689refseq (protein)np_001305073np_004916np_057898location (ucsc)chr 9: 33.44 – 33.45 mbchr 4: 41.09 – 41.1 mbpubmed searchwikidataview/edit humanview/edit mouse suberoylanilide hydroxamic acid (saha) (a hdac inhibitor) increases expression of aquaporin-3 in normal skin cells (keratinocytes). clinical significance aquaporin 3 levels are often lower in psoriasis than in healthy skin. aquaporin 3 is expressed more in atopic eczema. recent studies indicate that aquaporin 3 is overexpressed in many types of malignancies such as melanoma and primary effusion lymphomas as well as cancers of the lung, colon, stomach, esophagus, mouth, liver, and pancreatic duct. based on these as well as cell culture studies, it is suggested that this overexpression contributes to the growth and spread of at least some of these cancers and therefore may be a therapeutic target for the treatment of these cancers.