The image contains three panels labeled A, B, and C. Panel A shows a scatter plot comparing whole-nucleus G F P-S U M O fluorescence intensity before and after heat shock. Before heat shock shows low fluorescence intensity and less points, while after heat shock shows higher fluorescence intensity and more points. Panel B shows a graph which compares fluorescence intensity over relative time. A green shaded curve shows higher intensity with a peak at 50 minutes labeled onset of mitosis. After 50 minutes, the curve declines. A gray shaded curve below the green curve show relatively stable and lower intensity. Panel C displays a representative time-lapse sequence of a heat-shocked hypha co-expressing G F P-S U M O (green) and Histone H 1-R F P (magenta), with labels for nuclear enrichment, extruded remnent, and daughter nucleus. Time values include, 115 minutes, 144 minutes, 153 minutes, 159 minutes, 167 minutes, and 169 minutes; nuclear enrichment is at 144 minutes, extruded remnent is at 167 minutes, and two daughter nuclei are labeled ay 169 minutes.
Heat shock induces nuclear SUMO accumulation and focal enrichment at a site consistent with the preexisting nucleolar compartment. (A) Quantification of whole-nucleus GFP-SUMO fluorescence intensity before and after heat shock (42°C for 45 min). Each pair of points represents a single nucleus, with paired values connected by thin gray lines (n = 50 nuclei). Data were analyzed using a two-tailed paired t test (P < 0.0001). (B) Time-aligned GFP-SUMO fluorescence intensity traces from heat-shocked and non–heat-shocked hyphae, measured at a defined nuclear region corresponding to the nucleolar position. The green and gray lines represent the mean intensity for heat-shocked (n = 5 nucleoli) and non–heat-shocked (n = 4 nucleoli) cells, respectively; shaded regions indicate ±SD. The approximate timing of mitotic onset is indicated. (C) Representative time-lapse sequence of a heat-shocked hypha co-expressing GFP-SUMO (green) and histone H1-RFP (magenta), illustrating diffuse nuclear accumulation followed by focal SUMO enrichment prior to mitosis. This sequence corresponds to Video 7.