The genomic structure of the rat corticotropin releasing factor receptor - A member of the Class II G protein-coupled receptors

Isolation and structural characterization of the rat corticotropin releasing factor receptor (CRFR) gene was performed to determine the exon/intron organization of the coding region and the potential for splice variants, The CRFR gene contains 13 exons and 12 introns, and the positions of the exon/intron junctions are similar to those of other Class II G protein-coupled receptor genes including the parathyroid hormone and glucagon receptors, The promoter resides within 593 base pairs of the initiation codon and the major transcriptional start site at nucleotide -238. This domain does not possess a TATA box but contains multiple Spl and AP-2 sites upstream and downstream of the major transcriptional start site, Intron junctions were identified in the extracellular, transmembrane (TM), and cytoplasmic (C) domains of the CRFR, giving the potential for differential signal transduction by splice variants, CRFR cDNAs derived from rat Leydig cell mRNA included the pituitary Form A, which spans exons 1-13, and two splice variants with deletion of exon 3 or exons 7, 11, and 12, An evolutionary link between the intronless TM/C module of the glycoprotein hormone receptors and the intron-containing TM/C module of the CRFR is suggested by the common position of the luteinizing hormone receptor Form D alternate acceptor splice site and the CRFR intron 12.