Figure 6.

The luciferase activity arising from the construct containing the BUB1B promoter is regulated during the cell cycle. (A) COS-7 cells were transiently transfected with −464/−31 (open boxes) or −464/−196 (solid boxes) constructs. Cells were synchronized with a double thymidine block and released (time 0) and harvested at the indicated times for luciferase assays. Data are presented as the mean +/−SD of three independent experiments. (B) Gel retardation assay with the wt probe II in the absence (lane 1) or presence of COS-7 nuclear extracts from cells synchronized in G2/M (lanes 2–4) or G1/S (lanes 5–8). Reactions in lanes 3 and 6, 4 and 7, 8 were performed in the presence of unlabeled specific competitor (wt SBS), unspecific competitor (unsp) and anti-hStaf/ZNF143 antibody, respectively. Position of the specific complex is indicated with an arrow.