Figure 2

Major Intrinsic Protein Superfamily. Phylip rooted phylogenetic tree of aquaporin proteins from diverse species. Shown are aquaporins from mouse (m), rat (r), and human (h); from plants Arabidopsis thaliana (SIPs, TIPs) and soybean Glycine max (Nodulin 26); from bacteria E. coli GlpF and AqpZ; from intracellular parasites Trypanosoma cruzi (TcAQP) and Plasmodium falciparum (PfAQP); from nematodes C. elegans and C. briggsae; from fruitfly D. melanogaster and mosquito A. gambiae; from pufferfish T. nigroviridis. Aquaporins that transport glycerol or ions, in addition to water, are labeled by brackets on the right. Aquaporins hat transport only water are unlabelled. Aquaporins for which there is no known solute are labeled with a question mark. In many cases only one or two of the mammalian aquaporins in a specific group have been characterized. For example, TIP1.1 is a water-selective channel, but TIP5.1 has not been characterized; human and rat AQP6 are ion and water channels, but mouse AQP6 has not been characterized.