Corticotropin-releasing factor, CRF is a family

Protein family

A protein family is a group of evolutionarily-related proteins, and is often nearly synonymous with gene family. The term protein family should not be confused with family as it is used in taxonomy....

 of related neuropeptide

Neuropeptide

Neuropeptides are small protein-like molecules used by neurons to communicate with each other. They are neuronal signaling molecules, influence the activity of the brain in specific ways and are thus involved in particular brain functions, like analgesia, reward, food intake, learning and...

s in vertebrate

Vertebrate

Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

s. This family includes corticotropin-releasing hormone

Corticotropin-releasing hormone

Corticotropin-releasing hormone , originally named corticotropin-releasing factor , and also called corticoliberin, is a polypeptide hormone and neurotransmitter involved in the stress response...

, urotensin

Urotensin-II

Urotensin-II is a peptide ligand, initially isolated from the neurosecretory system of the Goby fish . For many years it was thought that U-II does not exhibit significant effects in mammalian systems; a view quickly overturned when it was demonstrated that Goby U-II produces slow relaxation of...

-I, urocortin

Urocortin

Urocortin is a protein that in humans is encoded by the UCN gene.Urocortin is a potent anorexigenic peptide of 40 amino acids that induces fed-like motor activity when administered centrally or peripherally in fasted animals. Urocortin belongs to the corticotropin-releasing factor family that...

 and sauvagine form a family . The family can be grouped into 2 separate paralogous lineages, with urotensin-I, urocortin and sauvagine in one group and CRF forming the other group. Urocortin and sauvagine appear to represent orthologues of fish urotensin-I in mammals and amphibians, respectively. The peptides have a variety of physiological effects on stress and anxiety, vasoregulation, thermoregulation

Thermoregulation

Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...

, growth and metabolism, metamorphosis and reproduction in various species, and are all released as prohormones.

Corticotropin-releasing hormone

Corticotropin-releasing hormone

Corticotropin-releasing hormone , originally named corticotropin-releasing factor , and also called corticoliberin, is a polypeptide hormone and neurotransmitter involved in the stress response...

(CRH) is a hormone found mainly in the paraventricular nucleus of the mammalian hypothalamus that regulates the release of corticotropin (ACTH) from the pituitary gland. From here, CRF is transported to the anterior pituitary, stimulating adrenocorticotropic hormone

Adrenocorticotropic hormone

Adrenocorticotropic hormone , also known as 'corticotropin', 'Adrenocorticotrophic hormone', is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological...

 (ACTH) release via CRF type 1 receptor

Corticotropin releasing hormone receptor 1

Corticotropin releasing hormone receptor 1 is a protein, also known as CRF1, with the latter now being the IUPHAR-recommended name...

s, thereby activating the hypothalamic–pituitary–adrenal axis (HPA) and thus glucocorticoid

Glucocorticoid

Glucocorticoids are a class of steroid hormones that bind to the glucocorticoid receptor , which is present in almost every vertebrate animal cell...

 release.

CRH is evolutionary related to a number of other active peptides. Urocortin

Urocortin

Urocortin is a protein that in humans is encoded by the UCN gene.Urocortin is a potent anorexigenic peptide of 40 amino acids that induces fed-like motor activity when administered centrally or peripherally in fasted animals. Urocortin belongs to the corticotropin-releasing factor family that...

 acts in vitro to stimulate the secretion of adrenocorticotropic hormone

Adrenocorticotropic hormone

Adrenocorticotropic hormone , also known as 'corticotropin', 'Adrenocorticotrophic hormone', is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological...

. Urotensin is found in the teleost caudal neurosecretory system and may play a role in osmoregulation

Osmoregulation

Osmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move...

 and as a corticotropin-releasing factor. Urotensin-I is released from the urophysis of fish, and produces ACTH and subsequent cortisol release in vivo. The nonhormonal portion of the prohormone is thought to be the urotensin binding protein (urophysin). Sauvagine , isolated from frog skin, has a potent hypotensive and diuretic effect.

Human proteins from this family

CRH

Corticotropin-releasing hormone

Corticotropin-releasing hormone , originally named corticotropin-releasing factor , and also called corticoliberin, is a polypeptide hormone and neurotransmitter involved in the stress response...

; UCN

Urocortin

Urocortin is a protein that in humans is encoded by the UCN gene.Urocortin is a potent anorexigenic peptide of 40 amino acids that induces fed-like motor activity when administered centrally or peripherally in fasted animals. Urocortin belongs to the corticotropin-releasing factor family that...

;