Activation of the G-CSFR promoter by AML1-MTG8.

(A) Schematic representation of the promoter region of G-CSFRand its deletion mutants. (B) Activation of the G-CSFR promoter by AML1-MTG8. LG cells expressing either vector, AML1b, AML1-MTG8 or a deletion mutant of AML1-MTG8, D487, were transfected with G-CSFR–luciferase (pGL3) using DEAE-dextran. Transfection efficiency was normalized by cotransfection with pRL-TK as an internal control. pGRP1400n; normal 1370 bp promoter, pGRP1400m; a mutant (2 base substitution) of the AML1 consensus site of pGRP1400n. (C) AML1b interferes with the enhancing activity of AML1-MTG8 on theG-CSFR promoter. Cells were cotransfected with pGRP1400n and either LNSX, LNSX-AML1b, or LNSX-AML1-MTG8. LNSX-AML1b was added in addition to the effector plasmid AML1-MTG8 at 0.3 μg, 1 μg, and 3 μg in lanes 2, 3, and 4, respectively. The total amount of effector DNA was 6 μg each. LNSX was used to adjust the total amount of DNA. (D) Activity of 5′ deletion mutants of the G-CSFRpromoter in L-G cells. Cells were cotransfected with each mutant and either 3 μg of LNSX, LNSX-AML1b, or LNSX-AML1-MTG8. The activity of the control vacant reporter with LNSX was designated as being equal to 1.