Function: Forms a water-specific channel that provides the plasma membranes of renal collecting duct with high permeability to water, thereby permitting water to move in the direction of an osmotic gradient.
Tissue Specificity: Expressed in renal collecting tubules. Belongs to the MIP/aquaporin (TC 1.A.8) family.
Post-translational modifications: Ser-256 phosphorylation is necessary and sufficient for expression at the apical membrane. Endocytosis is not phosphorylation-dependent.