Aquaporin 2

Aquaporin 2 (collecting duct)
Identifiers
Symbols	AQP2 ; AQP-CD; MGC34501; WCH-CD
External IDs	Template:OMIM5 Template:MGI HomoloGene: 20137
Gene ontology Molecular function Template:GNF GO Template:GNF GO Cellular component Template:GNF GO Template:GNF GO Template:GNF GO Template:GNF GO Biological process Template:GNF GO Template:GNF GO Template:GNF GO
RNA expression pattern
More reference expression data
Orthologs
Template:GNF Ortholog box
Species	Human	Mouse
Entrez	n/a	n/a
Ensembl	n/a	n/a
UniProt	n/a	n/a
RefSeq (mRNA)	n/a	n/a
RefSeq (protein)	n/a	n/a
Location (UCSC)	n/a	n/a
PubMed search	n/a	n/a

AQP2 is found in the apical cell membranes of the kidney's collecting duct principal cells and in intracellular vesicles located throughout the cell.

Regulation

It is the only aquaporin regulated by vasopressin.

This aquaporin is regulated in two ways by the peptide hormone vasopressin:

• short-term regulation (minutes) through trafficking of AQP2 vesicles to the apical region where they fuse with the apical plasma membrane
• long-term regulation (days) through an increase in AQP2 gene expression.

Clinical significance

Mutations in this channel are associated with nephrogenic diabetes insipidus, which can be either autosomal dominant or recessive.

Lithium, which is often used to treat bipolar disorder, can cause acquired diabetes insipidus by decreasing the expression of the AQP2 gene. This can result in debilitating increases in the rate of urine production.

The expression of the AQP2 gene is increased during conditions associated with water retention such as pregnancy and congestive heart failure.

See also

• Aquaporin

Further reading

• Bichet DG (2006). "Nephrogenic diabetes insipidus". Advances in chronic kidney disease. 13 (2): 96–104. doi:10.1053/j.ackd.2006.01.006. PMID 16580609.
• Robben JH, Knoers NV, Deen PM (2006). "Cell biological aspects of the vasopressin type-2 receptor and aquaporin 2 water channel in nephrogenic diabetes insipidus". Am. J. Physiol. Renal Physiol. 291 (2): F257–70. doi:10.1152/ajprenal.00491.2005. PMID 16825342.CS1 maint: Multiple names: authors list (link)
• Sasaki S, Fushimi K, Saito H; et al. (1994). "Cloning, characterization, and chromosomal mapping of human aquaporin of collecting duct". J. Clin. Invest. 93 (3): 1250–6. PMID 7510718.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Deen PM, Weghuis DO, Sinke RJ; et al. (1994). "Assignment of the human gene for the water channel of renal collecting duct Aquaporin 2 (AQP2) to chromosome 12 region q12-->q13". Cytogenet. Cell Genet. 66 (4): 260–2. PMID 7512890.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Uchida S, Sasaki S, Fushimi K, Marumo F (1994). "Isolation of human aquaporin-CD gene". J. Biol. Chem. 269 (38): 23451–5. PMID 7522228.CS1 maint: Multiple names: authors list (link)
• van Lieburg AF, Verdijk MA, Knoers VV; et al. (1994). "Patients with autosomal nephrogenic diabetes insipidus homozygous for mutations in the aquaporin 2 water-channel gene". Am. J. Hum. Genet. 55 (4): 648–52. PMID 7524315.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Saito F, Sasaki S, Chepelinsky AB; et al. (1994). "Human AQP2 and MIP genes, two members of the MIP family, map within chromosome band 12q13 on the basis of two-color FISH". Cytogenet. Cell Genet. 68 (1–2): 45–8. PMID 7525161.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Nielsen S, Chou CL, Marples D; et al. (1995). "Vasopressin increases water permeability of kidney collecting duct by inducing translocation of aquaporin-CD water channels to plasma membrane". Proc. Natl. Acad. Sci. U.S.A. 92 (4): 1013–7. PMID 7532304.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. PMID 8125298.
• Deen PM, Verdijk MA, Knoers NV; et al. (1994). "Requirement of human renal water channel aquaporin-2 for vasopressin-dependent concentration of urine". Science. 264 (5155): 92–5. PMID 8140421.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Oksche A, Möller A, Dickson J; et al. (1996). "Two novel mutations in the aquaporin-2 and the vasopressin V2 receptor genes in patients with congenital nephrogenic diabetes insipidus". Hum. Genet. 98 (5): 587–9. PMID 8882880.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Mulders SM, Knoers NV, Van Lieburg AF; et al. (1997). "New mutations in the AQP2 gene in nephrogenic diabetes insipidus resulting in functional but misrouted water channels". J. Am. Soc. Nephrol. 8 (2): 242–8. PMID 9048343.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Ma T, Yang B, Umenishi F, Verkman AS (1997). "Closely spaced tandem arrangement of AQP2, AQP5, and AQP6 genes in a 27-kilobase segment at chromosome locus 12q13". Genomics. 43 (3): 387–9. doi:10.1006/geno.1997.4836. PMID 9268644.CS1 maint: Multiple names: authors list (link)
• Canfield MC, Tamarappoo BK, Moses AM; et al. (1998). "Identification and characterization of aquaporin-2 water channel mutations causing nephrogenic diabetes insipidus with partial vasopressin response". Hum. Mol. Genet. 6 (11): 1865–71. PMID 9302264.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K; et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. PMID 9373149.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Vargas-Poussou R, Forestier L, Dautzenberg MD; et al. (1998). "Mutations in the vasopressin V2 receptor and aquaporin-2 genes in 12 families with congenital nephrogenic diabetes insipidus". J. Am. Soc. Nephrol. 8 (12): 1855–62. PMID 9402087.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Kuwahara M (1998). "Aquaporin-2, a vasopressin-sensitive water channel, and nephrogenic diabetes insipidus". Intern. Med. 37 (2): 215–7. PMID 9550615.
• Mulders SM, Bichet DG, Rijss JP; et al. (1998). "An aquaporin-2 water channel mutant which causes autosomal dominant nephrogenic diabetes insipidus is retained in the Golgi complex". J. Clin. Invest. 102 (1): 57–66. PMID 9649557.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Goji K, Kuwahara M, Gu Y; et al. (1998). "Novel mutations in aquaporin-2 gene in female siblings with nephrogenic diabetes insipidus: evidence of disrupted water channel function". J. Clin. Endocrinol. Metab. 83 (9): 3205–9. PMID 9745427.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
• Saito T, Ishikawa S, Ito T; et al. (1999). "Urinary excretion of aquaporin-2 water channel differentiates psychogenic polydipsia from central diabetes insipidus". J. Clin. Endocrinol. Metab. 84 (6): 2235–7. PMID 10372737.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)

External links

• Aquaporin+2 at the US National Library of Medicine Medical Subject Headings (MeSH)