Aquaporins facilitate the transport of water and small neutral solutes across cell membranes. Transports urea in yeast cells in a pH-independent manner. Tonoplast. Expressed in roots. Starts to be expressed in seedlings from 2 days ays after germination. Aquaporins contain two tandem repeats each containing three membrane-spanning domains and a pore-forming loop with the signature motif Asn-Pro-Ala (NPA). Belongs to the MIP/aquaporin (TC 1.A.8) family. TIP (TC 1.A.8.10) subfamily.