Neighbor-joining phylogenetic tree of exportins and importins that are most closely related to Exportin-5. The families are Exportin-5 (Xpo-5), Exportin-1 (Xpo-1), Exportin T (Xpo-T), and fungal importin Mtr10P. Phylogenetic reconstruction method, species colour-coding and nodes labeling of significance are the same as Fig. 1. The tree is unrooted. Locations of some specific isoforms from Homo sapiens, Arabidopsis thaliana and Caenorhabditis elegans (CE) that are mentioned in the text are annotated on the tree. Species name abbreviations are given in the Methods. The multiple sequence alignment file is given in Additional file 5.