Aquaporin 3 is a water channel protein. Aquaporins are a
family of small integral membrane proteins related to the major
intrinsic protein (MIP or AQP0). Aquaporin 3 is localized at the
basal lateral membranes of collecting duct cells in the kidney. In
addition to its water channel function, aquaporin 3 has been found
to facilitate the transport of nonionic small solutes such as urea
and glycerol, but to a smaller degree. It has been suggested that
water channels can be functionally heterogeneous and possess water
and solute permeation mechanisms.
