Anti-Aquaporin 4/AQP4 Antibody Picoband®

Aquaporin 4 is found in the basolateral cell membrane of principal collecting duct cells and provides a pathway for water to exit these cells. The gene of AQP4 is mapped to 18q11.2-q12.1. Similar to other aquaporins, the AQP4 gene is composed of 4 exons encoding 127, 55, 27, and 92 amino acids separated by introns of 0.8, 0.3, and 5.2 kb. Unlike other aquaporins, an alternative coding initiation sequence (designated exon 0) was located 2.7 kb upstream of exon 1. When spliced together, M1 and the subsequent 10 amino acids are encoded by exon 0; the next 11 amino acids and M23 are encoded by exon 1. AQP4 is expressed in astrocytes and is upregulated by insult to the central nervous system. And AQP4 is the predominant water channel in the brain and has an important role in brain water homeostasis. It is abundant in mammalian brain and is concentrated in astrocytic foot processes at the blood-brain barrier.

A synthetic peptide corresponding to a sequence at the C-terminus of human Aquaporin 4, different from the related mouse sequence by two amino acids, and from the related rat sequence by three amino acids.

1. Amiry-Moghaddam, M.; Otsuka, T.; Hurn, P. D.; Traystman, R. J.; Haug, F.-M.; Froehner, S. C.; Adams, M. E.; Neely, J. D.; Agre, P.; Ottersen, O. P.; Bhardwaj, A. : An alpha-syntrophin-dependent pool of AQP4 in astroglial end-feet confers biional water flow between blood and brain. Proc. Nat. Acad. Sci. 100: 2106-2111, 2003. 2. Agre P, Nielsen S (1996) . The aquaporin family of water channels in kidney. Nephrologie 17 (7) : 409–15. 3. Lennon, V. A.; Kryzer, T. J.; Pittock, S. J.; Verkman, A. S.; Hinson, S. R. : IgG marker of optic-spinal multiple sclerosis binds to the aquaporin-4 water channel. J. Exp. Med. 202: 473-477, 2005. 4. Lu, M.; Lee, M. D.; Smith, B. L.; Jung, J. S.; Agre, P.; Verdijk, M. A. J.; Merkx, G.; Rijss, J. P. L.; Deen, P. M. T. : The human AQP4 gene: definition of the locus encoding two water channel polypeptides in brain. Proc. Nat. Acad. Sci. 93: 10908-10912, 1996. 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.

Store at -20°C for one year from date of receipt. After reconstitution, at 4°C for one month. It can also be aliquotted and stored frozen at -20°C for six months. Avoid repeated freeze-thaw cycles.