This 41 amino acid neuroendocrine peptide is the key hypothalamic releasing factor in the mammalian stress response.
Glucocorticoids then mediate the body's adaptive response to stress.
CRH is also expressed in other regions of the brain and in the periphery where it mediates many of the endocrine, autonomic, and immunological effects of stress. We have focused on transcriptional regulation of the CRH gene by cAMP, calcium, and steroid hormones. This protein is distinct from the receptors, binds CRH with an affinity equal to or greater than that of the receptors, and is expressed in the pituitary and CNS of rodents and primates. In vitro, this binding protein appears to neutralize the biological activity of CRH and the recently discovered CRH-like peptide, urocortin. We are presently characterizing the expression, regulation, and activity of the CRH-BP using in situ hybridization histochemistry, RNase protection assays, gene transfer studies, and biochemical methods.