Fig. 1. Nma111p is a nuclear protein that interacts with the NPC. (A) Haploid cells whose endogenous Nma111p was C-terminally tagged with GFP were examined by direct immunofluorescence. A confocal fluorescence micrograph (left) and a coincident fluorescence/differential-interference-contrast image (right) is shown. (B) Immunogold-EM localisation of Nma111p-GFP at the NPC. Triton-X-100-extracted spheroplasts were preimmunolabelled with a polyclonal anti-GFP antibody directly conjugated to 8-nm colloidal gold. Selected examples of gold-labelled NPCs are shown in cross-sections along the NE. The antibody labelled the cytoplasmic face of the NPC (top) and the nuclear face of the NPC (bottom). c, cytoplasm; n, nucleus. (C) Quantitative analysis of the gold-particle distribution associated with the NPC relative to its two symmetry axes in Nma111p-GFP cells. The central plane of the NPC is within the NE, the eightfold symmetry axis is perpendicular to the plane of the NE. 68 gold particles were scored. Scale bars, 5 µm (A); 100 nm (B).