Aquaporin 11 (AQP11)

AQP11 has a unique asparagine-proline-alanine (NPA) box distinct from those of other AQPs, suggesting a different pore structure and function. Using Northern blot analysis, they detected highest expression of mouse Aqp11 in testis, followed by liver and kidney. Expression was much weaker in heart, brain, and muscle. Western blot analysis of mouse kidney membrane fractions detected Aqp11 at an apparent molecular mass of 26 kD, lower than the calculated molecular mass of 30 kD. Immunohistochemical analysis localized Aqp11 to mouse renal proximal tubule cells, where it showed a perinuclear distribution. Fluorescence-tagged Aqp11 localized with an endoplasmic reticulum marker.Human and rat AQPX1 share 81% amino acid identity.