Determination of the subunit composition of NFY complexes.

Nuclear extracts from HUVECs (5 μg) were incubated with IgG and anti-C/EBP (shown as CEB) antibodies as negative controls, and anti–NFY-A, anti–NFY-B, and anti–NFY-C antibodies (1 μg each). Following 3 hours of incubation at 4°C, the reaction mixtures were further incubated at room temperature for 15 minutes in the presence of either the IR probe that corresponds to sequences −30 to +1 and contains the CCAAT element (lanes 7-12), or the R probe corresponding to sequences +215 to +247 (lanes 1-6). Complexes formed were analyzed on an acrylamide gel as described for Figure 2.