AQP4 (aquaporin 4) is an intrinsic protein, and belongs to the family of aquaporin water channels, which consists of thirteen members. This gene is localized to human chromosome 18 q11-q12, and has four exons and three introns. The encoded protein has five loops, intervened by six transmembrane domains. Loops A, C and E face the extraplasmic region, and loops B and D are present in the cytoplasmic region. It is expressed in peripheral organs such as, lung, stomach and kidney. It is the predominant water channel expressed in central nervous system. It is expressed by astrocytes, and localizes preferentially to end-foot processes of astrocytes. It is present as two alternatively spliced forms- long one called M1 and the short one named M23.
Synonyms: Anti-AQP-4; Anti-Aquaporin-4; Anti-MIWC; Anti-Mercurial-insensitive water channel; Anti-WCH4
MDL Number: MFCD02262547
Storage: -20C
Application: All Prestige Antibodies Powered by Atlas Antibodies are developed and validated by the Human Protein Atlas (HPA) project (www.proteinatlas.org)and as a result, are supported by the most extensive characterization in the industry. The Human Protein Atlas project can be subdivided into three efforts: Human Tissue Atlas, Cancer Atlas, and Human Cell Atlas. The antibodies that have been generated in support of the Tissue and Cancer Atlas projects have been tested by immunohistochemistry against hundreds of normal and disease tissues and through the recent efforts of the Human Cell Atlas project, many have been characterized by immunofluorescence to map the human proteome not only at the tissue level but now at the subcellular level. These images and the collection of this vast data set can be viewed on the Human Protein Atlas (HPA) site by clicking on the Image Gallery link. To view these protocols and other useful information about Prestige Antibodies and the HPA, visit sigma.com/prestige.
Biochem Physiol Actions: AQP4 (aquaporin 4) is the major water transporter in brain, and is thought to be responsible for maintaining the water homeostasis in brain. Therefore, AQP4 might play a key role in the pathogenesis of brain edema. Studies show that this transporter is overexpressed in cerebral ischemia. Thus, it might have potential as a therapeutic target for ischemic brain edema. Polymorphisms in this gene are associated with response to brain injury, and the clinical outcome in patients with traumatic brain injury. The short isoform (M23) of AQP4 facilitates the formation of orthogonal array of particles (OAPs), and the size of OAP is determined by the ratio of short (M23): long (M1) isoforms. These OAPs are known to interact with the pathogenic auto-antibodies generated in neuromyelitis optica (NMO). Thus, further studies on this protein might provide insights into the pathogenesis and treatment of NMO.
Legal Information: Prestige Antibodies is a registered trademark of Sigma-Aldrich Co. LLC