Energy metabolism and behavior in the corticotropin-releasing factor family of peptides

Citation: Carr JA and Lovejoy DA (2015) Energy metabolism and behavior in the corticotropin-releasing factor family of peptides. This year, 2015, will mark the sixtieth anniversary of the seminal work by Guillemin and Rosenberg (1955) and Schally and Saffran (1955) which, along with the earlier work from Geoffrey Harris' lab, initiated the search for an adrenocorticotropin releasing factor that culminated with the discovery of corticotropin-releasing factor (CRF) in 1981 by Wylie Vale's laboratory (Vale et al., 1981). Since the 1980s, the CRF story has had many twists and turns from the finding that CRF and its receptors are located in many extra-hypothalamic brain areas and extending to the discovery that two genome duplications expanded the CRF peptide family hundreds of millions of years ago. Because of the early metazoan ancestry of CRF, this peptide has become ensconced in a number physiological processes. We now know that stress in vertebrates is comprised of a complex set of physiological actions that regulate organismal metabolism to promote protection of the individual and progeny from life-threatening situations. This stress response likely evolved before the earliest multicel-lular organisms yet has been retained throughout metazoan evolution. Vertebrates, in particular, have developed some of the most complex stress-regulating mechanisms. Integral to this stress response is CRF, and its paralogue, urocortin (urotensin-I/sauvagine) and a parallel paralogous lineage consisting of urocortin 2 and 3. Six review papers in this volume summarize some of the latest research on the role of CRF and urocortin (UCN) peptides in modulating behavior during stress. In addition, two new research studies present data supporting an ancient role for CRF/UCN receptors in social behavior and feeding , while two additional papers explore the role of extrahypothalamic CRF neurons in behavioral and endocrine responses. A consistent theme running through this set of papers is that many of the effects of CRF/UCN peptides on physiology and behavior are evolutionarily conserved. In their contribution, Chen et al. (2013) examine the evolutionary origins of the tenuerin C-terminal associated peptides (TCAP), peptides which may have predated the origin of the CRF peptide family. Chen et al. (2013) review data on the neuromodulatory actions of TCAP-1 and both its direct and indirect effects as an indirect modulator of CRF intracellular signaling. Feeding and intake of nutrients is essential for the success of any species. A stress-response, as regulated by the CRF family of peptides, generally has suppressive actions on appetite and …