Hydropathy plot models and transport characteristics of wild-type AQP1 and AQP10. (A) Model of AQP1. Each symbol corresponds to a single residue within a transmembrane domain (red), a connecting segment (pink), the XX/R filter (yellow), or the NPA motifs (black). Residues above the transmembrane domains face the extracellular side of the membrane. The cartoon was drawn with the program PLOT based on the hydropathy model of Murata et al. (2000). (B) Model of AQP10. Each symbol corresponds to a single residue in a transmembrane domain (blue), a connecting segment (pale blue), the XX/R filter (brown), or the NPA motifs (black). The cartoon was drawn with the program PLOT based on sequence alignments of transmembrane domains with AQP1. (C) Multiple alignment analysis of AQP family members with Clustal Omega. The residue segment used for each of the channels corresponds to the one that is flanked by green lines in A and B; the N and C termini were excluded from the analysis given that they are poorly conserved among the isoforms. AQP11 and AQP12 were also excluded given that they share much lower homologies with the other family members. Gray boxes correspond to transmembrane segments based on alignments with AQP1, and colored residues correspond to those that were interchanged between AQP1 and AQP10 in this study.