GPCRs are a large family of cell surface receptors that respond to a variety of external signals. Binding of a signaling molecule to a GPCR results in G protein activation, which in turn triggers the production of any number of second messengers.

Why is GPCR important?

In addition, GPCRs are involved in the transmission of external signals into the cell. The GPCR family includes receptors that are responsible for the recognition of light, taste, odours, hormones, pain, neurotransmitters and many other things. ... This is why the GPCR family is of huge pharmaceutical importance.

What is the role of G protein?

G proteins regulate metabolic enzymes, ion channels, transporter proteins, and other parts of the cell machinery, controlling transcription, motility, contractility, and secretion, which in turn regulate diverse systemic functions such as embryonic development, learning and memory, and homeostasis.