Characterization of the promoter of the human gene encoding the high-affinity IgG receptor: Transcriptional induction by γ-interferon is mediated through common DNA response elements

Expression of the high-affinity receptor for IgG (Fc_γRI) is restricted to cells of myeloid lineage and is induced by γ-interferon (IFN-γ) but not by IFN-α/β. The organization of the human Fc_γRI gene has been determined and the DNA elements governing its cell type-restricted transcription and IFN-γ induction are reported here. A 39-nucleotide sequence (IFN-γ response region, or GRR) is defined that is both necessary and sufficient for IFN-γ inducibility. Sequence analysis of the GRR reveals the presence of promoter elements initially defined for the major histocompatibility complex class II genes: i.e., X, H, and γ-IRE sequences. Comparison of a number of genes whose expression is induced selectively by IFN-γ indicates that the presence of these elements is a general feature of IFN-γ-responsive genes. Our studies suggest that the combination of X, H, and γ-IRE elements is a common motif in the pathway of transcriptional induction by this lymphokine.