PRIMARY STRUCTURE AND FUNCTIONAL EXPRESSION OF MOUSE PITUITARY AND HUMAN BRAIN CORTICOTROPIN-RELEASING FACTOR RECEPTORS

Corticotrophin-releasing factor (CRF) is the principal hypothalamic fa ctor governing the pituitary-adrenal axis, but the wide extra-pituitar y distribution of CRF and its receptors suggest a major role for this neuropeptide in the integration of the overall physiological and behav ioral responses of an organism to stress. We have cloned a CRF recepto r complementary DNA (cDNA) by expression in COS-7 cells of a cDNA libr ary from the AtT20 mouse pituitary tumour cell line. The cloned mouse cDNA was then used as a probe to isolate a human CRF receptor cDNA fro m a human brain cDNA library. The mouse and human cDNAs both encode 41 5 amino acid proteins that are 97% identical, containing seven putativ e transmembrane domains characteristic of G protein-coupled receptors. The CRF receptor shows homology with the receptors for growth hormone -releasing factor, vasoactive intestinal peptide, secretin, parathyroi d hormone, and calcitonin. COS-7 cells transfected with the mouse CRF receptor cDNA bind radiolabelled ovine CRF with high affinity and resp ond specifically to CRF by accumulation of intracellular cAMP. A 2.7 k b mRNA coding for the CRF receptor could be detected in AtT20 cells an d human cortex tissue. PCR analysis also detected the receptor transcr ipt in human pituitary, brainstem, and testis.