Class C G protein-coupled receptor (Class C GPCR)

Class C G protein-coupled receptors (GPCRs) represent a distinct family of cell surface receptors characterized by a large extracellular N-terminal domain, often referred to as the Venus flytrap domain, which facilitates the binding of diverse ligands including amino acids, ions, and small molecules (IUPHAR/BPS Guide to Pharmacology). This family includes several physiologically vital targets such as the metabotropic glutamate receptors (mGluRs), GABA-B receptors, the calcium-sensing receptor (CASR), and taste receptors (T1Rs), all of which are essential for mediating neurotransmission and maintaining systemic ion balance (UniProt). The CASR, for instance, is a critical regulator of calcium homeostasis, sensing minute changes in extracellular calcium to modulate parathyroid hormone secretion (StatPearls). Dysregulation of Class C GPCRs is linked to a wide range of conditions, including secondary hyperparathyroidism, chronic kidney disease, schizophrenia, and neurological disorders like Fragile X syndrome (PubMed). Pharmacological targeting of these receptors often utilizes allosteric modulators, such as the calcimimetic cinacalcet, which provide a more nuanced control of receptor activity compared to traditional agonists or antagonists (DrugBank).

Other names

Glutamate receptor familyFamily C G protein-coupled receptorVenus flytrap receptorsMultiple extracellular small molecules and metal ions

Allosteric modulation (positive and negative), agonism, and antagonism of receptor signaling activity.