FIG. 3.
CIF150 (hTAFII150) is a positive regulator of cyclin B1 and cyclin A transcription. (A) Purified CIF150 was visualized after SDS-PAGE by silver staining (20 μl loaded in lane 2). M, molecular size standards (in kilodaltons). (B) CIF150 is required for cyclin B1 and cyclin A transcription but not for IgH and CMV transcription. In vitro transcription was performed by using CIF150-depleted nuclear extracts (lane 1) alone or in combination with increasing amounts of recombinant CIF150 protein (lanes 2 to 4). (C) Cotransfection of increasing amounts of CIF150 expression plasmid with cyclin B1, cyclin A, CMV, and Fos promoter-driven luciferase reporter constructs. Relative luciferase units are shown in the upper panel, and fold stimulation is shown in the lower panel. The amount of CMV-derived vector in each transfection assay was kept constant by using an unrelated expression plasmid (pEVRF1-Ob). The values shown are the averages from at least four independent transfection experiments ± standard deviations (error bars).