Mutation of the conserved PU.1 site in the human MBP-P2 promoter abolishes cooperation with PU.1.

Mutations were introduced to the PU.1 core elements 1 and 2 of the pMBP(−117)–luciferase construct, as indicated in the figure. These were cotransfected with various combinations of the expression vectors for PU.1, GATA-1, and C/EBPε₃₂. At 24 hours after transfection, lysates were prepared and luciferase activity (RLU) was measured and normalized to renilla luciferase to control for transfection efficiency. The graph represents the average (± SD) of 2 experiments performed in triplicate.