Abstract
G protein-coupled receptors (GPCRs) are the major transducers of external stimuli and key therapeutic targets in many pathological conditions. When activated by different ligands, one receptor can elicit multiple signalling cascades that are mediated by G proteins or β-arrestin, a process defined as functional selectivity or ligand bias. However, the dynamic mechanisms underlying β-arrestin signalling remain unknown. Here by studying the cannabinoid receptor 1 (CB1R), we identify ligand-specific endocytic dwell times, that is, the time during which receptors are clustered into clathrin pits together with β-arrestins before endocytosis, as the mechanism controlling β-arrestin signalling. Agonists inducing short endocytic dwell times produce little or no β-arrestin signalling, whereas those eliciting prolonged dwell times induce robust signalling. Remarkably, extending CB1R dwell times by preventing endocytosis substantially increased β-arrestin signalling. These studies reveal how receptor activation translates into β-arrestin signalling and identify a mechanism to control this pathway.
Publication types
-
Research Support, American Recovery and Reinvestment Act
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Arachidonic Acids / pharmacology
-
Arrestins / genetics
-
Arrestins / metabolism*
-
Benzoxazines / pharmacology
-
Cannabinoid Receptor Agonists / pharmacology
-
Clathrin / genetics
-
Clathrin / metabolism
-
Embryo, Mammalian
-
Endocannabinoids / pharmacology
-
Endocytosis / drug effects
-
Endocytosis / physiology*
-
Gene Expression Regulation
-
Glycerides / pharmacology
-
HEK293 Cells
-
Hippocampus / cytology
-
Hippocampus / drug effects
-
Hippocampus / metabolism
-
Humans
-
Ligands
-
Morpholines / pharmacology
-
Naphthalenes / pharmacology
-
Neurons / cytology
-
Neurons / drug effects
-
Neurons / metabolism*
-
Primary Cell Culture
-
RNA, Small Interfering / genetics
-
RNA, Small Interfering / metabolism
-
Rats
-
Receptor, Cannabinoid, CB1 / antagonists & inhibitors
-
Receptor, Cannabinoid, CB1 / genetics
-
Receptor, Cannabinoid, CB1 / metabolism*
-
Signal Transduction
-
Time Factors
-
Transport Vesicles / drug effects
-
Transport Vesicles / metabolism*
-
beta-Arrestins
Substances
-
Arachidonic Acids
-
Arrestins
-
Benzoxazines
-
Cannabinoid Receptor Agonists
-
Clathrin
-
Endocannabinoids
-
Glycerides
-
Ligands
-
Morpholines
-
Naphthalenes
-
RNA, Small Interfering
-
Receptor, Cannabinoid, CB1
-
beta-Arrestins
-
(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone
-
glyceryl 2-arachidonate