Aquaporins facilitate the transport of water and small neutral solutes across cell membranes. Expressed in leaves and at lower levels in roots and anthers. 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. NIP (TC 1.A.8.12) subfamily.