Peptidergic G Protein-coupled Receptors

Peptides are a rapidly growing class of mediators whose activity regulates homeostasis as well as pathological processes. Most of the peptide-activated receptors belong to the superfamily of 7 transmembrane domain receptors coupled to G proteins. Peptides of different sizes (from a few to more than 100 aminoacids) activate peptidergic receptors by interacting at specific sites, that often differ from those where antagonists bind. Other receptors are activated by proteases that, by cleaving the receptor extracellular region, unmask a tethered ligand. G protein-coupled receptors for chemokines represent the way of entry of the HIV virus in target cells. The great impact of non peptide agonist/antagonists in current and future medicine reflects these large variety of functions and modes of activation of peptidergic G protein-coupled receptors.