Functions in regulating agonist-mediated G-protein coupled receptor (GPCR) signaling by mediating both receptor desensitization and resensitization processes. During homologous desensitization, beta-arrestins bind to the GPRK-phosphorylated receptor and sterically preclude its coupling to the cognate G-protein; the binding appears to require additional receptor determinants exposed only in the active receptor conformation. The beta-arrestins target many receptors for internalization by acting as endocytic adapters (CLASPs, clathrin-associated sorting proteins) and recruiting the GPRCs to the adapter protein 2 complex 2 (AP-2) in clathrin-coated pits (CCPs). However, the extent of beta-arrestin involvement appears to vary significantly depending on the receptor, agonist and cell type. Internalized arrestin-receptor complexes traffic to intracellular endosomes, where they remain uncoupled from G-proteins. Two different modes of arrestin-mediated internalization occur. Class A receptors, like
ADRB2,
OPRM1, ENDRA, D1AR and
ADRA1B dissociate from beta-arrestin at or near the plasma membrane and undergo rapid recycling. Class B receptors, like
AVPR2,
AGTR1,
NTSR1,
TRHR and
TACR1 internalize as a complex with arrestin and traffic with it to endosomal vesicles, presumably as desensitized receptors, for extended periods of time. Receptor resensitization then requires that receptor-bound arrestin is removed so that the receptor can be dephosphorylated and returned to the plasma membrane. Mediates endocytosis of
CCR7 following ligation of
CCL19 but not
CCL21. Involved in internalization of
P2RY1,
P2RY4,
P2RY6 and
P2RY11 and ATP-stimulated internalization of
P2RY2. Involved in phosphorylation-dependent internalization of
OPRD1 and subsequent recycling or degradation. Involved in ubiquitination of
IGF1R. Beta-arrestins function as multivalent adapter proteins that can switch the GPCR from a G-protein signaling mode that transmits short-lived signals from the plasma membrane via small molecule second messengers and ion channels to a beta-arrestin signaling mode that transmits a distinct set of signals that are initiated as the receptor internalizes and transits the intracellular compartment. Acts as signaling scaffold for MAPK pathways such as
MAPK1/3 (ERK1/2) and
MAPK10 (JNK3). ERK1/2 and JNK3 activated by the beta-arrestin scaffold are largely excluded from the nucleus and confined to cytoplasmic locations such as endocytic vesicles, also called beta-arrestin signalosomes. Acts as signaling scaffold for the
AKT1 pathway. GPCRs for which the beta-arrestin-mediated signaling relies on both
ARRB1 and
ARRB2 (codependent regulation) include
ADRB2,
F2RL1 and
PTH1R. For some GPCRs the beta-arrestin-mediated signaling relies on either
ARRB1 or
ARRB2 and is inhibited by the other respective beta-arrestin form (reciprocal regulation). Increases ERK1/2 signaling in
AGTR1- and
AVPR2-mediated activation (reciprocal regulation). Involved in
CCR7-mediated ERK1/2 signaling involving ligand
CCL19. Is involved in type-1A angiotensin II receptor/
AGTR1-mediated ERK activity. Is involved in type-1A angiotensin II receptor/
AGTR1-mediated
MAPK10 activity. Is involved in dopamine-stimulated
AKT1 activity in the striatum by disrupting the association of
AKT1 with its negative regulator PP2A. Involved in
AGTR1-mediated chemotaxis. Appears to function as signaling scaffold involved in regulation of
MIP-1-beta-stimulated
CCR5-dependent chemotaxis. Involved in attenuation of NF-kappa-B-dependent transcription in response to GPCR or cytokine stimulation by interacting with and stabilizing
CHUK. Suppresses UV-induced NF-kappa-B-dependent activation by interacting with
CHUK. The function is promoted by stimulation of
ADRB2 and dephosphorylation of
ARRB2. Involved in p53/
TP53-mediated apoptosis by regulating
MDM2 and reducing the
MDM2-mediated degradation of p53/
TP53. May serve as nuclear messenger for GPCRs. Upon stimulation of
OR1D2, may be involved in regulation of gene expression during the early processes of fertilization. Also involved in regulation of receptors other than GPCRs. Involved in endocytosis of
TGFBR2 and
TGFBR3 and down-regulates TGF-beta signaling such as NF-kappa-B activation. Involved in endocytosis of low-density lipoprotein receptor/
LDLR. Involved in endocytosis of smoothened homolog/Smo, which also requires
GRK2. Involved in endocytosis of
SLC9A5. Involved in endocytosis of
ENG and subsequent TGF-beta-mediated ERK activation and migration of epithelial cells. Involved in Toll-like receptor and IL-1 receptor signaling through the interaction with
TRAF6 which prevents
TRAF6 autoubiquitination and oligomerization required for activation of NF-kappa-B and
JUN. Involved in insulin resistance by acting as insulin-induced signaling scaffold for
SRC,
AKT1 and
INSR. Involved in regulation of inhibitory signaling of natural killer cells by recruiting
PTPN6 and
PTPN11 to
KIR2DL1. Involved in IL8-mediated granule release in neutrophils. Involved in the internalization of the atypical chemokine receptor
ACKR3.
UniProt