FIG. 2.

Overexpression of a dominant-negative (DN) NF-YA mutant prevents p53 association with CCAAT promoters. (A) NIH 3T3 cells were infected for 7 h with green fluorescent protein (GFP) control adenovirus (lanes 1 to 4), wild-type NF-YA adenovirus (lanes 5 to 8), or YAm29 adenovirus (lanes 9 to 12). Western blot analysis of overexpressed NF-YA is shown. (B) ChIP analysis with anti-NF-YB antibodies of chromatin derived from cells infected with the three viruses. The indicated bona fide NF-Y targets were PCR amplified. For each promoter, we show two amplifications at different PCR cycles. CTL, control; PLK, Polo-like kinase. (C) Same as panel B, except that wild-type NF-YA chromatin (YA wt) and YAm29 chromatin (YA DN) were analyzed with anti-NF-YB and anti-p53 antibodies (Ab). We included as controls the cyclin A promoter (single CCAAT box) and the p21 promoter (containing a bona fide p53 binding element but not CCAAT boxes).