What is the Origin of GPCR Kinases?

The name is derived from their substrate specificity: G protein-Coupled Receptors, which they Kinase, meaning they add a phosphate group to them. The term reflects their direct enzymatic action on this major class of receptors. This nomenclature highlights their essential role in the signal transduction machinery.

What is the Mechanism of GPCR Kinases?

The mechanism of action involves the GRK recognizing and binding to an activated, agonist-occupied GPCR. Upon binding, the GRK phosphorylates specific serine and threonine residues located on the receptor's intracellular tail. This phosphorylation event serves as a molecular tag, recruiting a protein called arrestin to the receptor. Arrestin binding sterically hinders the receptor's ability to interact with and activate G proteins, thereby rapidly attenuating the cellular response to the hormone or ligand.

GPCR Kinases ∞ Area

GPCR Kinases

Meaning

GPCR Kinases, or G protein-coupled receptor kinases (GRKs), are a family of serine/threonine protein kinases that play a critical regulatory role in the desensitization and signaling termination of G protein-coupled receptors (GPCRs), which are the largest family of cell surface receptors and mediate the actions of many hormones and neurotransmitters. These kinases act as crucial modulators of cellular responsiveness, preventing overstimulation and protecting the cell from chronic or excessive hormonal signaling. Their function is paramount in maintaining the delicate balance of the endocrine system’s communication networks. Dysregulation of GRKs can contribute to receptor insensitivity, impacting therapeutic effectiveness and physiological function.