Figure 7.

NR4A2 fails to enhance POU1F1-dependent Cdk9 recruitment at the Prl promoter. A. Schematic of relative positions of “upstream” (blue arrows), “promoter” (black arrows), and “downstream” (red arrows) primers, with known POU1F1 and predicted NR4A2 binding sites in blue and red ovals, respectively. Known POU1F1 sites are adapted from (21). B. Pit-1/0 cells were transfected with plasmids expressing Pou1f1 alone or with a combination of expression plasmids for both Pou1f1 and Nr4a2 (as in Fig. 6). ChIP was performed using an antibody against the Cdk9 subunit of the release factor P-TEFb. Cdk9 occupancy was assessed at the Gh and Prl promoters, at the autoregulated Pou1f1 promoter, and the promoter for the muscle-specific Myod gene. * indicates P < 0.05 as determined by 1-way analysis of variance. n = 3 biological replicates. NR4A2, nuclear orphan receptor transcription factor; POU1F1, pituitary-specific master regulatory transcription factor.