- Peptide (C)RQSVELHSPQSLPRGSKA, corresponding to amino acid residues 254-271 of rat AQP2 (Accession P34080). Intracellular, C-terminus.
- Expression of Aquaporin 2 in rat kidneyImmunohistochemical staining of rat kidney paraffin embedded region using Anti-Aquaporin 2-ATTO Fluor-550 Antibody (#AQP-002-AO), (1:50), (Red). AQP2 is detected in collecting ducts but not in thin segments of the loop of Henle. Nuclei are visualized with Hoechst 33342 (blue).
- Mouse mpkCCDc14 cells (Mamenko, M. et al. (2016) J. Am. Soc. Nephrol. 27, 2035.).
- King, L.S. et al. (2004) Nat. Rev. Mol. Cell Biol. 5, 687
- Deen, P.M. et al. (1994) Science 264, 92.
- Nielsen, S. et al. (2002) Physiol. Rev. 82, 205.
- Robben, J.H. et al. (2006) Am. J. Physiol. 291, F257.
Aquaporin 2 (AQP2) belongs to a family of membrane proteins that allow passage of water and certain other solutes through biological membranes. The family is composed of 13 members (AQP0 to AQP12). Little is known about the function of the two newest members, AQP11 and AQP12.
The aquaporins can be divided into two functional groups based on their permability characteristics: the aquaporins that are only permeated by water and the aquaglyceroporins that are permeated by water and other small solutes such as glycerol. This last group includes AQP3, AQP7, AQP9 and AQP10.1
The proteins present a conserved structure of six transmembrane domains with intracellular N- and C-termini. The functional channel is a tetramer but each subunit has a separate pore and therefore the functional channel unit, contains four pores.1
AQP2 expression is largely confined to the kidney, particularly in the renal collecting duct where it performs a key role in water absorption and urine concentration. In fact, mutations in the AQP2 gene produce hereditary nephrogenic diabetes insipidus, a disorder that results in the excretion of large volumes of urine.2
Under normal conditions, water homeostasis in the kidney is regulated through the anti-diuretic hormone vasopressin. Vasopressin is secreted from the pituitary gland and transported to the kidney through the blood where it binds to its receptor that is mainly expressed in cells of the collecting duct. The activated vasopressin receptor induces an increase in intracellular cAMP and subsequent PKA activation, which phosphorylates AQP2. This phosphorylation causes the translocation of AQP2 channels from intracellular vesicles to the cell membrane where it markedly increases water permeability.1,3,4
Species reactivity key:
Anti-Aquaporin 2 Antibody (#AQP-002) is a highly specific antibody directed against an epitope of the rat protein. The antibody can be used in western blot and immunohistochemistry applications. It has been designed to recognize the AQP2 channel from rat, mouse, and human samples.
Anti-Aquaporin 2-ATTO Fluor-550 Antibody (#AQP-002-AO) is directly labeled with an ATTO-550 fluorescent dye. ATTO dyes are characterized by strong absorption (high extinction coefficient), high fluorescence quantum yield, and high photo-stability. The ATTO-550 fluorescent label is related to the well known dye Rhodamine 6G and can be used with filters typically used to detect Rhodamine. Anti-Aquaporin 2-ATTO Fluor-550 Antibody is especially suited for experiments requiring simultaneous labeling of different markers.
- Multiplex staining of SK3 and Aquaporin 2 in mouse kidneyImmunohistochemical staining of mouse kidney sections using Anti-KCNN3 (KCa2.3, SK3) (N-term) Antibody (#APC-025) and Anti-Aquaporin 2-ATTO Fluor-550 Antibody (#AQP-002-AO). A. AQP2 staining (red). B. SK3 staining (green). C. Merge of A and B shows SK3 expression in AQP2 positive tubules (orange).
Adapted from Berrout, J. et al. (2014) PLoS ONE 9, e95149. with kind permission of Prof. O'Neil, R.G., Dpt. for Integrative Biology, the University of Texas Health Science Center Medical School, Houston, Texas, U.S.A.
- Human kidney sections (1:400).
Schwaderer, A.L. et al. (2016) J. Am. Soc. Nephrol. 27, 3175.
- Mouse kidney sections (1:200).
Li, Y. et al. (2016) PLoS ONE 11, e0155006.
- Mouse kidney sections (1:200).
Berrout, J. et al. (2014) PLoS ONE 9, e95149.
- Rat kidney sections (1:200).
Zaika, O. et al. (2013) J. Am. Soc. Nephrol. 24, 604.
- Mouse kidney sections. Also tested in TRPV4-/- mice.
Berrout, J. et al. (2012) J. Biol. Chem. 287, 8782.
- Mouse mpkCCDc14 cells.
Mamenko, M. et al. (2016) J. Am. Soc. Nephrol. 27, 2035.
- Jin, M. et al. (2012) Cell Calcium 51, 131.
- Mamenko, M. et al. (2011) PLoS ONE 6, e22824.