Figure 2.

The SUMO1∙SCE1 BiFC pair colocalizes with COP1 in nuclear bodies when catalytically active. A, Y2H analysis of the interaction between COP1 as a GAL4 BD fusion protein and the SUMO (machinery) proteins fused to the GAL4 AD domain. Yeast growth was scored 3 d after incubation on selective media at 30°C (−Leu [L] and Trp [W], −LW and His [H], −LWH + 1 mm 3-Amino-1,2,4-triazole [3AT], −LWH and Adenine [A]). B and C, Nuclear localization pattern of the SUMO1∙SCE1 BiFC pair in cells overexpressing RFP-COP1. B, ΔGG, conjugation-deficient SUMO variant; C, CAT1, catalytically inactive SCE1. Micrographs show from top-to-bottom the reconstituted BiFC signal, RFP-COP1, and their merged signals. Conditions were identical to those in Figure 1. Scale bars, 10 µm.