Aquaporin-2

Last updated

AQP2
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases AQP2 , AQP-CD, WCH-CD, aquaporin 2, NDI2
External IDs OMIM: 107777; MGI: 1096865; HomoloGene: 20137; GeneCards: AQP2; OMA:AQP2 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_000486

NM_009699

RefSeq (protein)

NP_000477

NP_033829

Location (UCSC) Chr 12: 49.95 – 49.96 Mb Chr 15: 99.48 – 99.48 Mb
PubMed search [3] [4]
Wikidata
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Aquaporin-2 (AQP-2) is found in the apical cell membranes of the kidney's collecting duct principal cells and in intracellular vesicles located throughout the cell. It is encoded by the AQP2 gene.

Contents

Regulation

It is the only aquaporin regulated by vasopressin. [5] The basic job of aquaporin 2 is to reabsorb water from the primary urine that flows into the nephron from the filtration of blood in the glomerulus through the Bowman's capsule. [6] Aquaporin 2 is in kidney epithelial cells and usually lies dormant in intracellular vesicle membranes. When it is needed, vasopressin binds to the cell surface vasopressin receptor thereby activating a signaling pathway that causes the aquaporin 2 containing vesicles to fuse with the plasma membrane, so the aquaporin 2 can be used by the cell. [7] This aquaporin is regulated in two ways by the peptide hormone vasopressin:

This aquaporin is also regulated by food intake. Fasting reduces expression of this aquaporin independently of vasopressin.

Clinical significance

Mutations in this channel are associated with nephrogenic diabetes insipidus, which can be autosomal dominant or recessive. Mutations in the vasopressin receptor cause a similar X-linked phenotype.

Lithium, which is often used to treat bipolar disorder, can cause acquired diabetes insipidus (characterized by the excretion of large volumes of dilute urine) by decreasing the expression of the AQP2 gene.

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

See also

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000167580 Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000023013 Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Dibas AI, Mia AJ, Yorio T (December 1998). "Aquaporins (water channels): role in vasopressin-activated water transport". Proceedings of the Society for Experimental Biology and Medicine. 219 (3): 183–199. doi:10.3181/00379727-219-44332. PMID   9824541. S2CID   28952956.
  6. Koeppen BM, Stanton BA (2019). Renal Physiology, Sixth Edition (6th ed.). Philadelphia, PA: Elsevier. pp. 25–40. ISBN   9780323595681.
  7. Lodish H, Berk A, Kaiser CA, Krieger M, Scott MP, Bretscher A, et al. (2008). Molecular Cell Biology (6th ed.). New York: Freeman. p.  445. ISBN   978-0-7167-7601-7.

Further reading