The linker between the zinc fingers and the CF of GATA-1 are required for p53 inhibition. (A) Schematic of deletion mutants of mouse GATA-1. (B) Transfections into 6C2 cells were performed, as described in the Figure 5 legend. A total of 150 ng of CMV Renilla luciferase, 0.5 μg of p53 Luc reporter plasmid, and 0.25 μg of CMV p53 was present in all samples, whereas various amounts of mouse wild-type GATA-1 expression vector or mutants were added as indicated (1, 2, or 3 μg). After normalization to Renilla luciferase activity, the firefly luciferase value for 1 μg of ΔCF was set to 100%, and the values for all other samples were correspondingly adjusted. The error bars indicate the standard deviation, and the experiments were performed between 4 and 7 times. We compared means for equal weights of the 2 highest DNA concentrations of ΔNFL, ΔNF, and ΔCF to wild type by Student t test, and *P < .05. (C) CMV Renilla luciferase and 1 μg of FR7Luc, a GATA-1–responsive reporter plasmid, were tranfected into QT6 fibrobasts with increasing amounts of mouse GATA-1 expression plasmid, as indicated (0.5, 1, or 2 μg). Normalization and error bars are as in (B), with values for 2 μg of wild-type GATA-1 set to 100%. The means for equal weights of the 2 lowest concentrations of wild-type were compared with those of all other constructs by Student t test; **P < .005 and ***P < .0005.