Regulation of Cell Type-Specific Mouse FcεRI β-Chain Gene Expression by GATA-1 Via Four GATA Motifs in the Promoter

Abstract

The FcR β-chain, a subunit of two related multisubunit receptor complexes, the FcεRI and FcγRIII, amplifies the mast cell response and is necessary for the cell surface expression of FcεRI in mouse. The transient reporter assay indicated that −69/+4 region is required for cell type-specific transcriptional regulation of mouse β-chain gene. EMSA using Abs against transcription factors or competitive oligonucleotides demonstrated that −58/−40 region (containing overlapping three GATA-1 sites, −53/−48, −46/−51, and −42/−47) and −31/−26 region (containing one GATA-1 site) are recognized by GATA-1. The promoter activity of β-chain was decreased by nucleotide replacements of the GATA-1 sites in mouse mast cell line PT18. Furthermore, exogenously produced GATA-1 up-regulated the promoter activity in CV-1 cells, which are negative in the β-chain production and the up-regulation was apparently suppressed by GATA-1 site mutations. These results indicate that cell type-specific transcription of mouse β-chain gene is regulated by GATA-1.