Urocortin III is a 38 amino acid

Amino acid

Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

 peptide

Peptide

Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

 that is a member of the CRF

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...

 family of peptides. Unlike 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...

 I, and similar to Urocortin II

Urocortin II

Urocortin 2 is an endogenous peptide in the corticotrophin-releasing factor family. Immunohistochemistry analysis of human myocytes has shown greater immunoreactivity of Ucn2 in myocytes of the failing heart compared to those of the healthy heart. Researchers suggest this is a result of an...

, Urocortin III is highly selective for the CRF2 receptor

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

 and does not show affinity for the CRF binding protein.

Urocortin II has been shown to have anorexigenic effects and hypotensive effects similar to Urocortin, but does not induce secretion of ACTH.