Belongs to the MIP/aquaporin (TC 1.A.8) family. Could be the product of a pseudogene. This is the C-terminal part of aquaporin-2. In strain S288c and many laboratory strains, a natural 11 bp deletion in position 109 leads to a frameshift, which disrupts the gene coding for this protein and produces two ORFs YLL052C and YLL053C. A contiguous sequence for aquaporin-2 can be found in strain Sigma 1278B (AC P0CD89).