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fl-arrestins in GPCR Desensitization

PAG Title fl-arrestins in GPCR Desensitization
PAG ID WIG000265
Type P
Source Link MSigDB
Publication Reference NA
PAG Description Role of -arrestins in the desensitization, sequestration and intracellular trafficking of GPCRs. Homologous desensitization of GPCRs (1) results from the binding of -arrestins (-arr) to agonist -occupied receptors following phosphorylation of the receptor by GRKs. -arrestin binding sterically precludes coupling between the receptor and heterotrimeric G proteins, leading to termination of signaling by G proteins effectors. Receptor-bound -arrestins also act as adapter proteins, binding to components of the clathrin endocytic machinery including clathrin, 2-adaptin (AP-2). Receptor sequestration (2) reflects the dynamin (Dyn)-dependent endocytosis of GPCRs via clathrin-coated pits. Once internalized, GPCRs exhibit two distinct patterns of -arrestin interaction. `Class A' GPCRs, for example the 2 adrenergic receptor, rapidly dissociate from -arrestin upon internalization. These receptors are trafficked to an acidified endosomal compartment, wherein the ligand is dissociated and the receptor dephosphorylated by a GPCR-specific protein phosphatase PP2A isoform, and are subsequently recycled to the plasma membrane (3). `Class B' receptors, for example the angiotensin II AT1a receptor, form stable receptor--arrestin complexes. These receptors accumulate in endocytic vesicles and are either targeted for degradation or slowly recycled to the membrane via as yet poorly defined routes.
Species Homo sapiens
Quality Metric Scores nCoCo Score: 490
Information Content Rich
Other IDs M7772
Base PAG ID WIG000265
Human Phenotyte Annotation
Curator PAGER curation team
Curator Contact PAGER-contact@googlegroups.com
Gene ID Gene symbol Gene name RP_score
Gene A Gene B Source SCORE

Gene A Gene B Mechanism Source
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