Biology:Aquaporin 1

Generic protein structure example

Aquaporin 1 is a protein that in humans is encoded by the AQP1 gene.

AQP1 is a widely expressed water channel, whose physiological function has been most thoroughly characterized in the kidney. It is found in the basolateral and apical plasma membranes of the proximal tubules, the descending limb of the loop of Henle, and in the descending portion of the vasa recta. Additionally, it is found in red blood cells, vascular endothelium, the gastrointestinal tract, sweat glands, lungs, and the central nervous system

It is not regulated by vasopressin (ADH).

Function

Aquaporins are a family of small integral membrane proteins related to the major intrinsic protein (MIP or AQP0). This gene encodes an aquaporin which functions as both a molecular water channel protein and as a non-selective cation channel gated by cyclic guanosine monophosphate (cGMP). It is a homotetramer with six bilayer spanning domains and N-glycosylation sites. The AQP1 monomer consists of six transmembrane alpha helices that are connected by five loops (A to E). The protein physically resembles channel proteins and is abundant in erythrocytes and renal tubes. The gene encoding this aquaporin is a possible candidate for disorders involving imbalance in ocular fluid movement.

See also

• Aquaporin
• Colton antigen system

Further reading

• "The aquaporin family of molecular water channels". Proceedings of the National Academy of Sciences of the United States of America 91 (14): 6255–8. July 1994. doi:10.1073/pnas.91.14.6255. PMID 7517546. Bibcode: 1994PNAS...91.6255K. 
• "Cellular and molecular biology of the aquaporin water channels". Annual Review of Biochemistry 68: 425–58. 2000. doi:10.1146/annurev.biochem.68.1.425. PMID 10872456. 
• "Embryonic epithelial membrane transporters". American Journal of Physiology. Renal Physiology 279 (6): F982-96. December 2000. doi:10.1152/ajprenal.2000.279.6.F982. PMID 11097616. 
• "New roles for old holes: ion channel function in aquaporin-1". News in Physiological Sciences 17 (2): 68–72. April 2002. doi:10.1152/nips.01372.2001. PMID 11909995. 
• Mitra, Alok K.; Ren, Gang; Reddy, Vijay S.; Cheng, Anchi; Froger, Alexandrine (2008). "The Architecture of a Water-Selective Pore in the Lipid Bilayer Visualized by Electron Crystallography in Vitreous Ice". Ion Channels: From Atomic Resolution Physiology to Functional Genomics. Novartis Foundation Symposia. pp. 33–50. doi:10.1002/0470868759.ch4. ISBN 978-0-470-84375-8. 
• "Role of RhAG and AQP1 in NH3 and CO2 gas transport in red cell ghosts: a stopped-flow analysis". Transfusion Clinique et Biologique 13 (1–2): 117–22. 2006. doi:10.1016/j.tracli.2006.03.004. PMID 16574458. 
• "Appearance of water channels in Xenopus oocytes expressing red cell CHIP28 protein". Science 256 (5055): 385–7. April 1992. doi:10.1126/science.256.5055.385. PMID 1373524. Bibcode: 1992Sci...256..385P. 
• "Isolation of the cDNA for erythrocyte integral membrane protein of 28 kilodaltons: member of an ancient channel family". Proceedings of the National Academy of Sciences of the United States of America 88 (24): 11110–4. December 1991. doi:10.1073/pnas.88.24.11110. PMID 1722319. Bibcode: 1991PNAS...8811110P. 
• "Erythrocyte Mr 28,000 transmembrane protein exists as a multisubunit oligomer similar to channel proteins". The Journal of Biological Chemistry 266 (10): 6407–15. April 1991. doi:10.1016/S0021-9258(18)38133-X. PMID 2007592. 
• "Identification, purification, and partial characterization of a novel Mr 28,000 integral membrane protein from erythrocytes and renal tubules". The Journal of Biological Chemistry 263 (30): 15634–42. October 1988. doi:10.1016/S0021-9258(19)37635-5. PMID 3049610. 
• "The Colton blood group locus. A linkage analysis". Transfusion 28 (5): 435–8. 1988. doi:10.1046/j.1537-2995.1988.28588337331.x. PMID 3166547. 
• "Membrane topology of aquaporin CHIP. Analysis of functional epitope-scanning mutants by vectorial proteolysis". The Journal of Biological Chemistry 269 (3): 1668–73. January 1994. doi:10.1016/S0021-9258(17)42079-5. PMID 7507481. 
• "Biogenesis and transmembrane topology of the CHIP28 water channel at the endoplasmic reticulum". The Journal of Cell Biology 125 (4): 803–15. May 1994. doi:10.1083/jcb.125.4.803. PMID 7514605. 
• "The water channel gene in human uterus". Biochemistry and Molecular Biology International 32 (2): 371–7. February 1994. PMID 7517253. 
• "The three-dimensional structure of human erythrocyte aquaporin CHIP". The EMBO Journal 13 (13): 2985–93. July 1994. doi:10.1002/j.1460-2075.1994.tb06597.x. PMID 7518771. 
• "Mutations in aquaporin-1 in phenotypically normal humans without functional CHIP water channels". Science 265 (5178): 1585–7. September 1994. doi:10.1126/science.7521540. PMID 7521540. Bibcode: 1994Sci...265.1585P. 
• "Human red cell aquaporin CHIP. I. Molecular characterization of ABH and Colton blood group antigens". The Journal of Clinical Investigation 94 (3): 1043–9. September 1994. doi:10.1172/JCI117418. PMID 7521882. 
• "Purification and structure-function analysis of native, PNGase F-treated, and endo-beta-galactosidase-treated CHIP28 water channels". Biochemistry 34 (7): 2212–9. February 1995. doi:10.1021/bi00007a015. PMID 7532004. 
• "Localization of the aquaporin 1 (AQP1) gene within a YAC contig containing the polymorphic markers D7S632 and D7S526". Genomics 25 (2): 599–600. January 1995. doi:10.1016/0888-7543(95)80070-3. PMID 7540589. https://zenodo.org/record/1258601. 

External links

• Aquaporin+1 at the US National Library of Medicine Medical Subject Headings (MeSH)
• Gallery of Aquaporin Simulations
• Human AQP1 genome location and AQP1 gene details page in the UCSC Genome Browser.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.