Beta-arrestin1 phosphorylation by GRK5 regulates G protein-independent 5-HT4 receptor signalling.
G protein-coupled receptors (GPCRs) have been found to trigger G protein-independent signalling. However, the regulation of G protein-independent pathways, especially their desensitization, is poorly characterized. Here, we show that the G protein-independent 5-HT(4) receptor (5-HT(4)R)-operated Src/ERK (extracellular signal-regulated kinase) pathway, but not the G(s) pathway, is inhibited by GPCR kinase 5 (GRK5), physically associated with the proximal region of receptor' C-terminus in both human embryonic kidney (HEK)-293 cells and colliculi neurons. This inhibition required two sequences of events: the association of beta-arrestin1 to a phosphorylated serine/threonine cluster located within the receptor C-t domain and the phosphorylation, by GRK5, of beta-arrestin1 (at Ser(412)) bound to the receptor. Phosphorylated beta-arrestin1 in turn prevented activation of Src constitutively bound to 5-HT(4)Rs, a necessary step in receptor-stimulated ERK signalling. This is the first demonstration that beta-arrestin1 phosphorylation by GRK5 regulates G protein-independent signalling.
Barthet
Gaël
G
Institut de Génomique Fonctionnelle, Universités de Montpellier, CNRS, Montpellier, France.
Carrat
Gaëlle
G
Cassier
Elizabeth
E
Barker
Breann
B
Gaven
Florence
F
Pillot
Marion
M
Framery
Bérénice
B
Pellissier
Lucie P
LP
Augier
Julie
J
Kang
Dong Soo
DS
Claeysen
Sylvie
S
Reiter
Eric
E
Banères
Jean-Louis
JL
Benovic
Jeffrey L
JL
Marin
Philippe
P
Bockaert
Joël
J
Dumuis
Aline
A
D019390:Arrestins / Q000096:biosynthesis*; D002460:Cell Line; D054774:G-Protein-Coupled Receptor Kinase 5 / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D009154:Mutation; D009474:Neurons / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D044422:Receptors, Serotonin, 5-HT4 / Q000378:metabolism*; D012694:Serine / Q000737:chemistry; D000071557:beta-Arrestins; D019061:src-Family Kinases / Q000378:metabolism
D019390:Arrestins; D010455:Peptides; D034741:RNA, Small Interfering; D000071557:beta-Arrestins; D044422:Receptors, Serotonin, 5-HT4; D012694:Serine; D019061:src-Family Kinases; D054774:G-Protein-Coupled Receptor Kinase 5; C517898:GRK5 protein, human; D019204:GTP-Binding Proteins