Cloning and characterization of a short variant of the corticotropin-releasing factor receptor subtype from rat amygdala

Biochem Biophys Res Commun. 1999 Mar 24;256(3):692-6. doi: 10.1006/bbrc.1999.0392.


We have identified and characterized a cDNA encoding a novel isoform of the corticotropin-releasing factor (CRF) receptor, referred to as CRF2alpha-tr, from the rat amygdala cDNA library. The nucleotide sequence of the cloned cDNA has a structure of an alternatively spliced form of the CRF2alpha receptor, which contains unspliced introns 6 and 7 in the message, and encodes a 236-amino-acid truncated protein that comprises three unique transmembrane domains. Northern blot analysis shows that the CRF2alpha-tr receptor is more strongly expressed in the rat amygdala, thalamus, and hypothalamus than the intact CRF2alpha receptor. Western blot analysis also reveals that the CRF2alpha-tr protein can be expressed in transfected COS-7 cells as well as CRF2alpha. Furthermore, this receptor binds rat/human CRF with almost the same low affinity (Kd = 12.7 nM) as the CRF2alpha and without accumulation of intracellular cAMP. Interestingly, it does not bind sauvagine or rat urocortin. These findings suggest that this truncated CRF receptor is the major isoform of CRF2alpha receptor mRNA transcripts in the amygdala and would mediate some functions of CRF pathways in the central nervous system.

MeSH terms

  • Alternative Splicing / genetics*
  • Amino Acid Sequence
  • Amygdala / metabolism*
  • Animals
  • Binding Sites
  • Blotting, Northern
  • Blotting, Western
  • COS Cells
  • Cloning, Molecular
  • Corticotropin-Releasing Hormone / metabolism
  • Corticotropin-Releasing Hormone / pharmacology
  • Cyclic AMP / metabolism
  • Glycosylation
  • Humans
  • Hypothalamus / metabolism
  • Introns / genetics
  • Molecular Sequence Data
  • Molecular Weight
  • Organ Specificity
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Rats
  • Receptors, Corticotropin-Releasing Hormone / chemistry
  • Receptors, Corticotropin-Releasing Hormone / genetics*
  • Receptors, Corticotropin-Releasing Hormone / metabolism
  • Thalamus / metabolism


  • Protein Isoforms
  • RNA, Messenger
  • Receptors, Corticotropin-Releasing Hormone
  • Corticotropin-Releasing Hormone
  • Cyclic AMP