Figure 7.

Recently repressed genes localize to the nuclear periphery throughout the cell cycle. (A) Strains having the lac operator array integrated either at INO1 or GAL1 were shifted from activating conditions to repressing conditions. After 3 h, cells were harvested, fixed, and processed for immunofluorescence. Cells were classified according to their bud morphology as in Figure 1 and, within each class, the percentage of cells in which the gene localized at the nuclear periphery was determined. (B) Newly born daughter cells having the lac operator array integrated at INO1 were purified by centrifugal elutriation under activating conditions or after 3 h of repression. Cells were harvested at the indicated times after elutriation, fixed, and processed for immunofluorescence. (C) nup1Δ cells having the lac operator array integrated at INO1 were transformed with either a vector, wild-type NUP1 or nup1ΔP1ΔP2. Cells were harvested either under activating conditions or after 3 h of repression, fixed, and processed for immunofluorescence. The blue, hatched line represents the level of colocalization of the lac repressor spot with the nuclear envelope predicted by chance (Brickner and Walter, 2004).