(A) Localization of EGFP-tagged Nup133 proteins in HeLa cells. Cells, co-stained with the NPC marker mAb414, were analyzed 48 h after transfection. In contrast to full length Nup133 (A–C), showing punctate nuclear rim staining, the non-Nup107-binding mutant Nup133 (L973E L976E) is dispersed over the cytoplasm and largely excluded from the nucleus and nuclear envelope (D–F). (B) Localization of EGFP-tagged Nup107 proteins in HeLa cells. Cells, co-stained with mAb414, were analyzed 48 h after transfection. EGFP-tagged Nup107 lacking the last ~250 residues shows punctate nuclear rim staining that overlaps with the mAb414 signal (D–F), similar to full length Nup107 (A–C). In contrast, the Nup133-binding C-terminus of Nup107 shows a dispersed EGFP-signal, with only a slight concentration at the nuclear envelope (G-J).