Molecular Evolution and in silico Structural Characterization of Plant Aquaporins (TIP)
n this work the evolutionary history of plant aquaporins is analyzed, notably the TIPs (Tonoplastic Intrinsic Proteins), aquaporins historically related to Tonoplasts with a series of functions attributed to water and solute transport, especially nitrogen. The evolutionary analyses performed based on sequences extracted from NCBI utilizing phylogenetic trees suggest the existence of 6 major groups originating from orthology events (TIPs 1, 2.1, 2.2, 3, 4 and 5), besides recent duplications in families of economic interest, such as Brassicaceae, Solanaceae, Poaceae and Fagaceae. Positive selection analyses evidenced probable events occurring in Brassicaceae and Fagaceae, in particular in the region of the so-called Loop C that, by modeling, was shown to be closely linked to the outer membrane of the tonoplast.
Finally, important positions (NPA, ar/R(arginine aromatic)) and FP (Froger's position) filters) were gauged, suggesting that a Threonine at the P1 position of the FPs may be an as yet unreported TIP signature.