Cloning, structural characterization, and chromosomal localization of the gene encoding the human prostaglandin E-2 receptor EP2 subtype

Northern blot analysis of human placental RNA using a probe to the 5' end o f the human prostaglandin E-2 (PGE(2)) EP2 receptor subtype coding region r evealed the existence of a high abundance, low molecular weight transcript. To investigate the origin of this transcript, and its possible relationshi p to the human EP2 mRNA, we have cloned and characterized the gene encoding the human PGE(2) EP2 receptor subtype, identified transcriptional initiati on and termination sites in two tissues (spleen and thymus), and determined its chromosomal localization. The human EP2 gene consists of two exons sep arated by a large intron, utilizes a common initiation site in both spleen and thymus at 1113 bp upstream of the translation initiation site, and has 3' transcript termini at 1140 bp and 1149 bp downstream of the translation stop site in spleen and thymus respectively. Southern and fluorescence in s itu hybridization analysis demonstrated the human EP2 gene to be a single c opy gene located in band 22 of the long arm of chromosome 14 (14q22). Thoug h our initial interest in this gene was to investigate potential differenti al splicing of the human EP2 gene in placenta, this work demonstrates that the atypical transcript observed in placenta probably arises from a distinc t, yet related, gene. Knowledge of the sequence, structure, and transcripti on events associated with the human EP2 gene will enable a broader understa nding of its regulation and potential role in normal physiology and disease . (C) 1999 Elsevier Science B.V. All rights reserved.