Genomic organization and characterization of the gene encoding bovine prostaglandin F2alpha receptor

We isolated genomic clones for bovine prostaglandin (PG) F2alpha receptor by the standard plaque hybridization method, using the cDNA fragments of bovine PGF2alpha receptor (PGF2alphaR) as probe DNAs. The coding regions of this receptor gene were interspersed by a large intron sequence (33 kb) at the splice junction in the sixth transmembrane domain. The 5'-RACE experiments revealed two alternative transcription start points (tsp), indicating the existence of two potential promoter regions. The major promoter, which was named promoter region A, was located upstream of exon 1 and lacked the typical TATA sequence and CAAT box but had three GC boxes with an overall high GC content. Another putative promoter, region B, was found upstream of exon 2 and had both a TATA-like sequence and a CAAT-like box with several potential binding sites for transcription factors. Southern blot analysis indicated that a single copy gene in the haploid genome encodes PGF2alphaR. Promoter activities of these two putative promoter regions were assayed in the bovine luteal cells, and one of them (promoter region A) was activated by phorbol 12-myristate 13-acetate (TPA) treatment.