Figure 1.

Pom33, and to a lower extent its paralogue Per33, are associated with NPCs. (A and B) Fluorescence microscopy analysis of Pom33-GFP (A) and Per33-GFP (B) in wt and nup133Δ cells expressing Nup49-mCherry. Spinning disk confocal images of single-channel fluorescence for GFP and mCherry are shown (left) as well as the merge (right). Bar, 5 µm. (C) Immunolocalization of GFP-tagged Pom33 at nuclear pores. Cryosections of Pom33-GFP cells were successively labeled with anti-GFP (detected using ProtA 10-nm gold particles) and with mAb414 (detected using ProtA 15-nm gold particles). (a) Typical patterns of Pom33-GFP localization at NPCs (detected based on NE structure and mAb414 labeling) as well as a section encompassing a nucleus are presented. Arrows point to 10-nm gold particles recognizing the GFP moiety of Pom33-GFP at nuclear pores. Arrowheads point to 10-nm gold particles localized outside of the NE. The cytoplasmic faces of the NE are oriented toward the top of each micrograph. (b) Statistical analysis of the distribution of anti-GFP–associated gold particles in control (expressing no GFP fusion protein), Pom33-GFP, Per33-GFP, and Ndc1-GFP cells. For each strain, the total number of anti-GFP–associated gold particles (n₁) and of cryosectioned cells (n₂) analyzed, as well as the percentage of GFP-associated gold particles localized at NPCs relative to the entire NE (NPC + NE), are indicated.