Comparison of nucleoporin localization with an ER lumenal protein, Kar2, innpa2-1/sec13andnpa1-1/sec23cells. Cells were shifed to 34° for the indicated times and processed for double-label IF with the monoclonal antibody mAb414 (Nups) and the rabbit polyclonal anti-Kar2 antibody. As the GFP-Nups were still present in these cells, the Nup signal resulted from a combination of GFP-Nic96, Nup170-GFP and the Nups recognized by mAb414. A. Wild-type (WT) and npa2-1/sec13 panels are shown where the 0, 1,2, and 4 hr. time points are exposed for the same time. The 4 hr.' panels show the same cell field as 4 hr. with decreased exposure times. B. Panels showing anti-Nup signal in npa1-1/sec23 cells were collected for the same exposure times as in A. Kar2 exposure times are one quarter of those in A, as the signal was brighter in these cells. Arrowheads denote cells in which the expanded ER network is most evident.