Sequence and organization of the human N-formyl peptide receptor-encoding gene

The human FPR1 gene encodes the N-formyl peptide receptor, a G protein-coupled receptor (GPCR) that mediates the activation of mature myeloid cells by bacterial N-formyl oligopeptides. To investigate the molecular basis for myeloid-specific production of this receptor, we have cloned and sequenced FPRL The gene is organized into three exons and two introns that span 6 kb. The coding block lacks introns. Yet, the transcription start point ( tsp) is separated from the start codon by 4902 bp consisting of three exons and two large introns. Two mRNAs are produced by alternative splicing of exon 2 in HL-60 neutrophils and normal blood monocytes. The region 5′ to the tsp contains three pyrimidine-rich segments, a feature that has been observed in other myeloid-specific genes. One complete Alu repeat is found in each intron and in the 3′-flanking region 317 bp downstream of the polyadenylation signal. Thus, FPR1 is a small myeloid-specific gene that is expressed as two alternatively spliced mRNAs encoding the same protein.