Figure 5.

Nup107 rearrangement in anaphase. (A) As mitosis progresses through anaphase, the outer rims of the DNA masses (labeled by histone 4-CFP; H4) seem to collect ER membranes (marked by YFP with an ER retention signal) that are later incoporated into the newly forming nuclei (arrow). The outline of the cell is indicated by a profile in the first image. D, daughter cell; and M, mother cell. Time is given in minutes. Bar, 3 μm. Also see Supplemental Material. (B) Colocalization of Nup107-RFP (107) and histone 4-GFP-labeled chromosomes (H4) shows that the nucleoporin leaves the DNA and occurs at the outward edge of the separating chromosome masses during spindle elongation. In late anaphase B, Nup107 concentrates in small areas. Bar, 3 μm. (C) Line-scan analysis of an anaphase B spindle demonstrates that traces of Nup107-RFP are still found on the chromosomes (arrow), whereas most of the protein concentrates at the poles of the separating DNA. Bar, 3 μm. (D) In anaphase B, the new envelope begins to form at the outward rim of the chromosomes. Although Nup107 becomes incorporated into the newly forming NE, the other nucleoporins (Nup214, Pom152) are not yet concentrated at the new NE. Bar, 1.5 μm. Also see Supplemental Material.