Aquaporin 4

AQP4
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3GD8
Identifiers
Aliases	AQP4, aquaporin 4, HMIWC2, MIWC, WCH4
External IDs	OMIM: 600308 MGI: 107387 HomoloGene: 37507 GeneCards: AQP4
Gene ontology Molecular function • water channel activity • transporter activity • water transmembrane transporter activity • glycerol channel activity Cellular component • cytoplasm • integral component of membrane • plasma membrane • basolateral plasma membrane • membrane • external side of plasma membrane • integral component of plasma membrane Biological process • water transport • ion transmembrane transport • multicellular organismal water homeostasis • renal water homeostasis • transport • cellular response to interferon-gamma • glycerol transport • cellular water homeostasis Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	361	11829
Ensembl	ENSG00000171885	ENSMUSG00000024411
UniProt	P55087	P55088
RefSeq (mRNA)	NM_001650 NM_004028 NM_001317384 NM_001317387	NM_009700 NM_001308641 NM_001308642 NM_001308643 NM_001308644 NM_001308645 NM_001308646 NM_001308647 NM_001317729
RefSeq (protein)	NP_001641.1 NP_004019.1	NP_001295570.1 NP_001295571.1 NP_001295572.1 NP_001295573.1 NP_001295574.1 NP_001295575.1 NP_001295576.1 NP_033830.2 NP_001304658.1
Location (UCSC)	Chr 18: 26.85 – 26.87 Mb	Chr 18: 15.39 – 15.4 Mb
PubMed search	[1]	[2]
Wikidata

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Aquaporin 4 also known as AQP4 is a protein which in humans is encoded by the AQP4 gene.^[3] AQP4 belongs to the aquaporin family of integral membrane proteins that conduct water through the cell membrane.

Function

AQP4 is constitutively expressed in the basolateral cell membrane of principal collecting duct cells in the kidney and provide a pathway for water to exit these cells.^[4]

AQP4 is also expressed in astrocytes and is upregulated by direct insult to the central nervous system.^[5]

Pathology

Aquaporin-4 is the primary autoimmune target in neuromyelitis optica,^[6][7] in which AQP4-specific IgG antibodies target astrocytic AQP4, resulting in complement activation and inflammation.^[8]

See also

• Aquaporins

References

1. "Human PubMed Reference:".
2. "Mouse PubMed Reference:".
3. Jung JS, Bhat RV, Preston GM, Guggino WB, Baraban JM, Agre P (December 1994). "Molecular characterization of an aquaporin cDNA from brain: candidate osmoreceptor and regulator of water balance". Proceedings of the National Academy of Sciences of the United States of America. 91 (26): 13052–6. doi:10.1073/pnas.91.26.13052. PMC 45579. PMID 7528931.
4. Agre P, Nielsen S (1996). "The aquaporin family of water channels in kidney". Nephrologie. 17 (7): 409–15. PMID 8987045.
5. Nagelhus EA, Mathiisen TM, Ottersen OP (2004). "Aquaporin-4 in the central nervous system: cellular and subcellular distribution and coexpression with KIR4.1". Neuroscience. 129 (4): 905–13. doi:10.1016/j.neuroscience.2004.08.053. PMID 15561407.
6. Lennon VA, Kryzer TJ, Pittock SJ, Verkman AS, Hinson SR (August 2005). "IgG marker of optic-spinal multiple sclerosis binds to the aquaporin-4 water channel". J. Exp. Med. 202 (4): 473–7. doi:10.1084/jem.20050304. PMC 2212860. PMID 16087714.
7. Bradl M, Lassmann DH (September 2008). "Anti-aquaporin-4 antibodies in neuromyelitis optica: how to prove their pathogenetic relevance?" (PDF). International MS Journal / MS Forum. 15 (3): 75–8. PMID 18812056.
8. Papadopoulos MC, Bennett JL, Verkman AS (Aug 12, 2014). "Treatment of neuromyelitis optica: state-of-the-art and emerging therapies.". Nature reviews. Neurology. 10: 493–506. doi:10.1038/nrneurol.2014.141. PMID 25112508.

Further reading

• Strand L, Moe SE, Solbu TT, Vaadal M, Holen T (2009). "Roles of aquaporin-4 isoforms and amino acids in square array assembly". Biochemistry. 48 (25): 5785–93. doi:10.1021/bi802231q. PMID 19445480.
• Wu H, Zhang Z, Li Y, Zhao R, Li H, Song Y, Qi J, Wang J (2010). "Time course of upregulation of inflammatory mediators in the hemorrhagic brain in rats: correlation with brain edema". Neurochem Int. 57 (3): 248–53. doi:10.1016/j.neuint.2010.06.002. PMID 20541575.
• Goodyear MJ, Crewther SG, Junghans BM (2009). "A role for aquaporin-4 in fluid regulation in the inner retina". Vis. Neurosci. 26 (2): 159–65. doi:10.1017/S0952523809090038. PMID 19366470.
• Matsushita T, Matsuoka T, Isobe N, Kawano Y, Minohara M, Shi N, Nishimura Y, Ochi H, Kira J (2009). "Association of the HLA-DPB1*0501 allele with anti-aquaporin-4 antibody positivity in Japanese patients with idiopathic central nervous system demyelinating disorders". Tissue Antigens. 73 (2): 171–6. doi:10.1111/j.1399-0039.2008.01172.x. PMID 19140826.
• Rubino E, Rainero I, Vaula G, Crasto F, Gravante E, Negro E, Brega F, Gallone S, Pinessi L (2009). "Investigating the genetic role of aquaporin4 gene in migraine". The journal of headache and pain. 10 (2): 111–4. doi:10.1007/s10194-009-0100-z. PMC 3451641. PMID 19209385.
• Benarroch EE (2007). "Aquaporin-4, homeostasis, and neurologic disease". Neurology. 69 (24): 2266–8. doi:10.1212/01.wnl.0000286385.59836.e2. PMID 18071147.
• Ho JD, Yeh R, Sandstrom A, Chorny I, Harries WE, Robbins RA, Miercke LJ, Stroud RM (2009). "Crystal structure of human aquaporin 4 at 1.8 A and its mechanism of conductance". Proc. Natl. Acad. Sci. U.S.A. 106 (18): 7437–42. doi:10.1073/pnas.0902725106. PMC 2678640. PMID 19383790.
• Assereto S, Mastrototaro M, Stringara S, Gazzerro E, Broda P, Nicchia GP, Svelto M, Bruno C, Nigro V, Lisanti MP, Frigeri A, Minetti C (2008). "Aquaporin-4 expression is severely reduced in human sarcoglycanopathies and dysferlinopathies". Cell Cycle. 7 (14): 2199–207. doi:10.4161/cc.7.14.6272. PMID 18641458.
• Dibas A, Yang MH, He S, Bobich J, Yorio T (2008). "Changes in ocular aquaporin-4 (AQP4) expression following retinal injury". Mol. Vis. 14: 1770–83. PMC 2559817. PMID 18836575.
• Sorani MD, Zador Z, Hurowitz E, Yan D, Giacomini KM, Manley GT (2008). "Novel variants in human Aquaporin-4 reduce cellular water permeability". Hum. Mol. Genet. 17 (15): 2379–89. doi:10.1093/hmg/ddn138. PMC 2733814. PMID 18511455.
• Ng WH, Hy JW, Tan WL, Liew D, Lim T, Ang BT, Ng I (2009). "Aquaporin-4 expression is increased in edematous meningiomas". Journal of Clinical Neuroscience. 16 (3): 441–3. doi:10.1016/j.jocn.2008.04.028. PMID 19153045.
• Nishiyama S, Ito T, Misu T, Takahashi T, Kikuchi A, Suzuki N, Jin K, Aoki M, Fujihara K, Itoyama Y (2009). "A case of NMO seropositive for aquaporin-4 antibody more than 10 years before onset". Neurology. 72 (22): 1960–1. doi:10.1212/WNL.0b013e3181a82621. PMID 19487655.
• Misu T, Fujihara K, Itoyama Y (May 2008). "Neuromyelitis optica and anti-aquaporin 4 antibody – an overview". Brain Nerve (in Japanese). 60 (5): 527–37. PMID 18516975.
• Dibas AI, Mia AJ, Yorio T (1998). "Aquaporins (water channels): role in vasopressin-activated water transport". Proc. Soc. Exp. Biol. Med. 219 (3): 183–99. doi:10.3181/00379727-219-44332. PMID 9824541.
• Doi H, Matsushita T, Isobe N, Matsuoka T, Minohara M, Ochi H, Kira JI (2009). "Hypercomplementemia at relapse in patients with anti-aquaporin-4 antibody". Mult. Scler. 15 (3): 304–10. doi:10.1177/1352458508099139. PMID 19028829.
• Pittock SJ, Lennon VA (2008). "Aquaporin-4 autoantibodies in a paraneoplastic context". Arch. Neurol. 65 (5): 629–32. doi:10.1001/archneur.65.5.629. PMID 18474738.
• Matsushita T, Isobe N, Matsuoka T, Shi N, Kawano Y, Wu XM, Yoshiura T, Nakao Y, Ishizu T, Kira JI (2009). "Aquaporin-4 autoimmune syndrome and anti-aquaporin-4 antibody-negative opticospinal multiple sclerosis in Japanese". Mult. Scler. 15 (7): 834–47. doi:10.1177/1352458509104595. PMID 19465451.
• Graber DJ, Levy M, Kerr D, Wade WF (2008). "Neuromyelitis optica pathogenesis and aquaporin 4". Journal of Neuroinflammation. 5: 22. doi:10.1186/1742-2094-5-22. PMC 2427020. PMID 18510734.
• Baba T, Nakashima I, Kanbayashi T, Konno M, Takahashi T, Fujihara K, Misu T, Takeda A, Shiga Y, Ogawa H, Itoyama Y (2009). "Narcolepsy as an initial manifestation of neuromyelitis optica with anti-aquaporin-4 antibody". J. Neurol. 256 (2): 287–8. doi:10.1007/s00415-009-0139-4. PMID 19266146.
• Xu H, Zhang Y, Wei W, Shen L, Wu W (2009). "Differential expression of aquaporin-4 in human gastric normal and cancer tissues". Gastroenterol. Clin. Biol. 33 (1 Pt 1): 72–6. doi:10.1016/j.gcb.2008.07.010. PMID 19112001.
• Kadohira I, Abe Y, Nuriya M, Sano K, Tsuji S, Arimitsu T, Yoshimura Y, Yasui M (2008). "Phosphorylation in the C-terminal domain of Aquaporin-4 is required for Golgi transition in primary cultured astrocytes". Biochem. Biophys. Res. Commun. 377 (2): 463–8. doi:10.1016/j.bbrc.2008.09.155. PMID 18854171.

External links

• Aquaporin 4 at the US National Library of Medicine Medical Subject Headings (MeSH)