Overview
- Peptide (C)REIKGKETNMADSYH, corresponding to amino acid residues 14-28 of rat AQP8 (Accession P56405). Intracellular, N-terminus.
- Rat pancreas and small intestine lysates (1:200-1:400).
Western blot analysis of rat small intestine membranes:1. Anti-Aquaporin 8 Antibody (#AQP-008), (1:200).
2. Anti-Aquaporin 8 Antibody, preincubated with Aquaporin 8 Blocking Peptide (#BLP-QP008).
Western blot analysis of rat pancreas membranes:1. Anti-Aquaporin 8 Antibody (#AQP-008), (1:400).
2. Anti-Aquaporin 8 Antibody, preincubated with Aquaporin 8 Blocking Peptide (#BLP-QP008).
- Rat pancreas and lung sections (paraffin embedded), (1:100).
Aquaporin 8 (AQP-8) belongs to a family of membrane proteins that allow passage of water and certain other solutes through biological membranes.1 The family is composed of 13 members (AQP-0 to AQP-12). Little is known about the function of the two newest members, AQP-11 and AQP-12.
The aquaporins can be divided into two functional groups based on their permability characteristics: the aquaporins that are permeated primarily by water and include besides AQP-8, AQP-1, AQP-2, AQP4 and AQP-5, and the aquaglyceroporins that are permeated by water and other small solutes such as glycerol. This last group includes AQP-3, AQP-7, AQP-9 and AQP-10.
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.2
AQP-8 is expressed along the gastrointestinal tract including small intestine, colon, pancreas and liver and also in other organs such as testis, lung and kidney.
The physiological function of AQP-8 is not entirely clear but studies suggest that it has an important role in colonic water adsorption and hepatocyte bile formation.3,4 Interestingly, AQP-8 expression is markedly altered in gastrointestinal disorders such as ulcerative colitis and inflammatory bowel disease.5
