Figure 4.

Channel formation is a late event in NPC assembly. To ask whether the nuclear intermediates that did not show diffusion channels by 30 min at 14°C were competent to develop such channels, the diffusion assay in Figure 3B was performed for both 30 min and 60 min at 14°C. Only nuclei showing closed nuclear envelopes (CNE) according to the anti-DNA antibody staining assay were analyzed for 3-kDa dextran uptake and were quantitated. At 30 min at 14°C, only 4% of intact nuclear intermediates showed internal Alexa488-3 kDa dextran. By 60 min at 14°C, however, 100% of the intact nuclear intermediates showed internal protected Alexa488-3 kDa dextran. Scale bars, 10 μm.