Figure 2.

Vacuole-associated nuclear bulges, blebs, and intravacuolar vesicles. (A) Electron micrographs of a vacuole-associated nuclear envelope bulge (a) and blebs (b and c) (V, vacuole; N, nucleus). YEF473a cells were processed for TEM as described in MATERIAL AND METHODS. (B) Confocal images of extreme nuclear exvaginations in two starved pep4-Δ cells expressing P_CUP1-NVJ1-EYFP and stained with FM4-64 (see MATERIALS AND METHODS). Nvj1p-EYFP (a), FM4-64 (b), and differential interference contrast overlay (c). Arrow in a points to a thin tether connecting the intravacuolar structure to the nucleus. Arrows in b point to FM4-64–stained intravacuolar membrane vesicles. (C) Nuclear envelope blebs and vesicles in cNvj1p-EYFP–expressing cells. Images show cNvj1p-EYFP (a), FM4-64 (b), and overlay (c) of a and b with Hoechst and differential interference contrast. Arrows point to intravacuolar vesicles. (D) Nuclear envelope blebbing is dependent on Vac8p. Nvj1p-EYFP–labeled blebs and vesicles were monitored in VAC8 (a and b) and vac8-Δ cells (c and d) in rich (YPD) (a and c) and starvation (SD-N) (b and d) media. Cells were grown in ScGlu, P_CUP1-NVJ1:EYFP expression induced for 1 h with 0.1 mM Cu²⁺, stained with FM4-64, and starved for 3 h in SD-N, or incubated in YPD for the same time period, as described in MATERIALS AND METHODS. Arrows indicate PMN structures.