Cloning and Characterization of a Short Variant of the Corticotropin-Releasing Factor Receptor Subtype from Rat Amygdala

International Union of Pharmacology. XXXVI. Current Status of the Nomenclature for Receptors for Corticotropin-Releasing Factor and Their Ligands

“…Three functional splice variants (Lovenberg et al, 1995b;Kostich et al, 1998) and a truncation variant (Miyata et al, 1999) have been identified for the mammalian CRF 2 receptor. The CRF 2(a) receptor variant is only expressed in nonmammalian species (Dautzenberg et al, 1997;Arai et al, 2001;Pohl et al, 2001), whereas the 430 -438 amino acid CRF 2(b) receptor and the CRF 2(a) receptor are both expressed in mammals (Kishimoto et al, 1995;Lovenberg et al, 1995b;Perrin et al, 1995;Stenzel et al, 1995;Valdenaire et al, 1997;Palchaudhuri et al, 1999).…”

“…In rodents, CRF 2(a) receptor mRNA is expressed primarily in brain neurons whereas CRF 2(b) receptor mRNA is detected in non-neuronal brain structures such Myers et al, 1998;Grammatopoulos et al, 1999;Miyata et al, 1999). The symbols { and } indicate the deletion of a 40-amino acid exon in a nonfunctional splice variant of the human CRF 1 receptor (Ross et al, 1994) whereas the symbol ] represents the common splice site for the three CRF 2 variants CRF 2(a) , CRF 2(b) , and CRF 2(c) .…”

Site-specific overexpression of corticotropin-releasing hormone (CRH) in the mouse brain – modelling central CRH system hyperactivity

“…Finally, the 397 amino acid CRH 2γ receptor is exclusively found in humans (Kostich et al, 1998) (Palchaudhuri et al, 1999). In addition to the functional splice variants, a truncated CRH 2α mutant (CRH 2avar) has been identified in the rat (Miyata et al, 1999). This receptor is lacking all sequences Cterminal to the third transmembrane helices.…”

Corticotrophin Releasing Hormone: Its Potential for a Role in Human Myometrium

“…The two CRH receptors are encoded by separate genes, with R1 present on the long arm of chromosome 17 at 17q12-q22 (Vamvakopoulos & Sioutopoulou, 1994) and R2 located on the short arm of chromosome 7 at 7p21-p15 (Meyer et al 1997). The subtypes share significant sequence homology of approximately 70 % and both exist in several isoforms as a result of alternative gene splicing, with four isoforms of each receptor subtype identified to date: CRH R1-a, -b, -c and -d (Chen et al 1993;Ross et al 1994;Grammatopoulos et al 1999) and CRH R2-a, -a truncated, -b and -y (Kishimoto et al 1995;Lovenberg et al 1995;Liaw et al 1996;Kostich et al 1998;Miyata et al 1999). The CRH R1-a receptor is a 415 amino acid protein which is activated efficiently by picomolar concentrations of CRH, generating intracellular cAMP via adenylate cyclase.…”

“…The most recent of the R2 variants identified, CRH R2-a truncated, is an unusual, alternatively spliced form of the CRF2-a receptor containing unspliced introns 6 and 7 in the message, resulting in a truncated protein of 236 residues that comprises three unique transmembrane domains. This receptor isoform binds CRH with high affinity but without accumulation of intracellular cAMP, leading to the proposal that it may function either as a dominant negative inhibitor of the full-length receptor, or, by analogy with the 5-HT3 receptor, as a ligand-gated ion channel (Miyata et al 1999). However, there have not as yet been any reports as to which ion channel may be involved.…”