Fig. 5. A block in cell division reveals phosphorylation-mediated regulation of the autonomous activity of the Op18 N-terminus. Cells were transfected with the indicated NR-helix derivative or vector alone (Vec-Co) as in Fig. 3. Cells were either non-induced or induced to express ectopic proteins for 24 hours. DNA was stained with propidium iodide and analyzed by flow cytometry. The inserts shows the effect of nocodazole (0.5 µM) on Op18(1-57)-NR-helix-, Op18(25-57)-NR-helix- and NR-helix-expressing cells. Data are representative of three independent experiments.