C/EBPα inhibits the transactivation capacity of the PU.1 activation domain.

Transient transfection in 293T cells with expression plasmids of C/EBPα, activation domain of PU.1 fused to the DNA-binding domain of Gal4, and Gal4-VP16. A minimal promoter with Gal4 DNA-binding sites only (pGal4-luc) was used as reporter construct. p(C/EBP)2TK was used as a control reporter for C/EBPα. Luciferase activities were measured 24 hours after transfection.