September 2022
"Background and purpose: The interaction of arrestins with G-protein coupled receptors (GPCRs) desensitizes agonist-dependent receptor responses and often leads to receptor internalization. GPCRs that internalize without arrestin have been classified as "class A" GPCRs whereas "class B" GPCRs co-internalize with arrestin into endosomes. The interaction of arrestins with GPCRs requires both agonist activation and receptor phosphorylation. Here, we ask the question whether agonists with very slow off-rates can cause the formation of particularly stable receptor-arrestin complexes."