Expression of constitutively active NFAT1 increases A1 mRNA levels in FcϵRI-stimulated mast cells. (A) RT-PCR analysis was used to determine the levels of A1 mRNA in C57 cells transiently transfected with vectors expressing constitutively active NFAT1, NFAT2, or empty vector. The cells were left untreated or were activated by FcϵRI crosslinking. Amplification of GAPDH was used as control. Overexpression of NFAT1, but not NFAT2, resulted in increased levels of A1 mRNA. Representative results from 2 independent experiments are shown. (B) Real-time quantitative PCR analysis of A1 mRNA shows increased levels of A1 expression in C57 cells expressing constitutively active NFAT1 compared with cells transfected with empty vector. Data are presented as mean plus or minus SEM from 3 independent experiments.