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1.A.8.9.1
Aquaporin 3. 95% identical to the human orthologue. Poorly permeable to water, but more permeable to glycerol and arsenic trioxide (Palmgren et al. 2017).  It is expressed in the plasma membrane of basal epidermal cells in the skin; loss of function prevents skin tumorigenesis and epidermal cell proliferation (Hara-Chikuma and Verkman, 2008).  The human orthologue also transports both water and glycerol and is the predominant AQP in skin (Jungersted et al. 2013). It's function is necessary for normal proliferation of colon cancer cells due to glycerol uptake (Li et al. 2016). Aqp3 is implicated in cancer progression to the metastatic state as its function promotes cell migration and cell shape plasticity.  Its synthesis is regulated by the AhR (aryl hydrocarbon (pollutant) receptor or dioxin receptor), a transcription factor triggered by environmental pollutants (Bui et al. 2016). Trefoil factor (TFF) peptides increase cell water permeability and induce prodcution of Aqp3 (Marchbank and Playford 2018). Although AQP3 and other similar transmembrane proteins do not themselves transport drugs, changes in their expression levels can cause changes in cell membrane fluidity, thus affecting drug absorption rates (Ikarashi et al. 2019).  AQP3 levels are elevated in human endometrioid carcinoma (Watanabe et al. 2020). AQP3 and AQP5 play important roles in spermatogenesis and sperm maturation in dogs (Mirabella et al. 2021). AQP-1, 3 and 8 levels in amniotic fluid were measured in patients suffering from polyhydramnios. They were compared to the levels observed in control subjects, and their relationship with maternal factors and neonatal issues was analyzed. AQP-1, 3, 8 levels physiologically fluctuated, AQP-1 levels were the lowest and AQP-3 the highest, with a decrease at the end of pregnancy (Guibourdenche et al. 2021). The human ortholog, Aqp3 (Q92482) is 95% identical. It transports water, glycerol and urea, and is the blood group antigen, GIL (Roudier et al. 2002). Intra-endolymphatic sac steroids have regulatory effects on inner ear AQP-3 expression via the vestibular aqueduct and modulate the homeostasis of endolymphatic fluids (Kitahara et al. 2003).  

Accession Number:P47862
Protein Name:AQP3
Length:292
Molecular Weight:31384.00
Species:Rattus norvegicus (Rat) [10116]
Number of TMSs:6
Location1 / Topology2 / Orientation3: Membrane1 / Multi-pass membrane protein2
Substrate water, glycerol

Cross database links:

RefSeq: NP_113891.1   
Entrez Gene ID: 65133   
Pfam: PF00230   
KEGG: rno:65133   

Gene Ontology

GO:0016021 C:integral to membrane
GO:0015250 F:water channel activity
GO:0055085 P:transmembrane transport
GO:0006833 P:water transport

References (3)

[1] “Cloning and expression of AQP3, a water channel from the medullary collecting duct of rat kidney.”  Echevarria M.et.al.   7526388
[2] “The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).”  The MGC Project Teamet.al.   15489334
[3] “Molecular cloning and expression of a member of the aquaporin family with permeability to glycerol and urea in addition to water expressed at the basolateral membrane of kidney collecting duct cells.”  Ishibashi K.et.al.   7517548

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Predict TMSs (Predict number of transmembrane segments)
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FASTA formatted sequence
1:	MGRQKELMNR CGEMLHIRYR LLRQALAECL GTLILVMFGC GSVAQVVLSR GTHGGFLTIN 
61:	LAFGFAVTLA ILVAGQVSGA HLNPAVTFAM CFLAREPWIK LPIYTLAQTL GAFLGAGIVF 
121:	GLYYDAIWAF AGNELVVSGP NGTAGIFATY PSGHLDMVNG FFDQFIGTAA LIVCVLAIVD 
181:	PYNNPVPRGL EAFTVGLVVL VIGTSMGFNS GYAVNPARDF GPRLFTALAG WGSEVFTTGQ 
241:	NWWWVPIVSP LLGSIGGVFV YQLMIGCHLE QPPPSTEAEN VKLAHMKHKE QI