Protocolpedia - The Encyclopedia Of Lab Protocols

G Protein Coupled Receptors (GPCRs) are proteins embedded in the surface of cells. GPCRs comprise the largest superfamily of proteins in the body. More than 1,000 different GPCRs have been identified since the first receptors were cloned. These proteins receive chemical signals from outside the cell and pass the signal into the cell, so that the cell can respond to the signal. The structures of the endogenous ligands for GPCRs are exceptionally diverse. They include biogenic amines such as norephnephrine and serotonine, peptides, glycoproteins, lipids, nucleotides, ions, and proteases. The sensation of exogenous stimuli, such as light, odors, and taste, is also mediated by this class of receptors. Activation of the receptor causes an effector inside the cell to produce a second signal chemical, which eventually triggers the cell to react to the original external chemical signal.............