Figure 4.

A nucleolar localization signal exists in the carboxy terminus of Rpp38. Swiss 3T3 fibroblasts were transfected with pEGFP-Rpp38(1-245) (A–C and G–J) or with pEGFP-Rpp38(246-283) (D–F and K–N). Construct maps are shown in Fig. 1 A. 48 h after transfection, living cells were examined (A–F) using confocal microscopy, or first fixed and subjected to indirect immunofluorescence using antibody against nucleolar protein B23 (G–J and K–N). DIC (A, D, G, and K), GFP (B, E, I, and M, green), B23 (H and L, red), and overlays (C, F, J, and N) are shown. Arrows point to nucleoli. Bars: C and F, 5 μm; J and N, 2.5 μm.