scholarly journals The Glucagon-like Peptide-2 Receptor C Terminus Modulates β-Arrestin-2 Association but Is Dispensable for Ligand-induced Desensitization, Endocytosis, and G-protein-dependent Effector Activation

2005 ◽  
Vol 280 (23) ◽  
pp. 22124-22134 ◽  
Author(s):  
Jennifer L. Estall ◽  
Jacqueline A. Koehler ◽  
Bernardo Yusta ◽  
Daniel J. Drucker
Keyword(s):  
Cell Surface ◽  
G Protein ◽  
Receptor Expression ◽  
Receptor Internalization ◽  
Cell Surface Receptor ◽  
Receptor Desensitization ◽  
C Terminus ◽  
The Family ◽  
Surface Receptor ◽  
Glucagon Like Peptide

Classic models of receptor desensitization and internalization have been largely based on the behavior of Family A G-protein-coupled receptors (GPCRs). The glucagon-like peptide-2 receptor (GLP-2R) is a member of the Family B glucagon-secretin GPCR family, which exhibit significant sequence and structural differences from the Family A receptors in their intracellular and extracellular domains. To identify structural motifs that regulate GLP-2R signaling and cell surface receptor expression, we analyzed the functional properties of a series of mutant GLP-2Rs. The majority of the C-terminal receptor tail was dispensable for GLP-2-induced cAMP accumulation, ERK1/2 activation, and endocytosis in transfected cells. However, progressive truncation of the C terminus reduced cell surface receptor expression, altered agonist-induced GLP-2R trafficking, and abrogated protein kinase A-mediated heterologous receptor desensitization. Elimination of the distal 21 amino acids of the receptor was sufficient to promote constitutive receptor internalization and prevent agonist-induced recruitment of β-arrestin-2. Site-directed mutagenesis identified specific amino acid residues within the distal GLP-2R C terminus that mediate the stable association with β-arrestin-2. Surprisingly, although the truncated mutant receptors failed to interact with β-arrestin-2, they underwent homologous desensitization and subsequent resensitization with kinetics similar to that observed with the wild-type GLP-2R. Our data suggest that, although the GLP-2R C terminus is not required for coupling to cellular machinery regulating signaling or desensitization, it may serve as a sorting signal for intracellular trafficking. Taken together with the previously demonstrated clathrin and dynamin-independent, lipid-raft-dependent pathways for internalization, our data suggest that GLP-2 receptor signaling has evolved unique structural and functional mechanisms for control of receptor trafficking, desensitization, and resensitization.

scholarly journals Lipid Raft-dependent Glucagon-like Peptide-2 Receptor Trafficking Occurs Independently of Agonist-induced Desensitization

2004 ◽  
Vol 15 (8) ◽  
pp. 3673-3687 ◽  
Author(s):  
Jennifer L. Estall ◽  
Bernardo Yusta ◽  
Daniel J. Drucker
Keyword(s):  
Cell Surface ◽  
G Protein ◽  
Lipid Raft ◽  
Receptor Activation ◽  
Receptor Internalization ◽  
Cell Surface Receptor ◽  
G Protein Coupled Receptor ◽  
Endosomal Acidification ◽  
Glucagon Like Peptide ◽  
G Protein Coupled

The intestinotrophic and cytoprotective actions of glucagon-like peptide-2 (GLP-2) are mediated by the GLP-2 receptor (GLP-2R), a member of the class II glucagon-secretin G protein-coupled receptor superfamily. Although native GLP-2 exhibits a short circulating half-life, long-acting degradation-resistant GLP-2 analogues are being evaluated for therapeutic use in human subjects. Accordingly, we examined the mechanisms regulating signaling, internalization, and trafficking of the GLP-2R to identify determinants of receptor activation and desensitization. Heterologous cells expressing the transfected rat or human GLP-2R exhibited a rapid, dose-dependent, and prolonged desensitization of the GLP-2–stimulated cAMP response and a sustained GLP-2–induced decrease in levels of cell surface receptor. Surprisingly, inhibitors of clathrin-dependent endocytosis failed to significantly decrease GLP-2R internalization, whereas cholesterol sequestration inhibited ligand-induced receptor internalization and potentiated homologous desensitization. The hGLP-2R localized to both Triton X-100–soluble and –insoluble (lipid raft) cellular fractions and colocalized transiently with the lipid raft marker caveolin-1. Although GLP-2R endocytosis was dependent on lipid raft integrity, the receptor transiently associated with green fluorescent protein tagged-early endosome antigen 1–positive vesicles and inhibitors of endosomal acidification attenuated the reappearance of the GLP-2R on the cell surface. Our data demonstrate that GLP-2R desensitization and raft-dependent trafficking represent distinct and independent cellular mechanisms and provide new evidence implicating the importance of a clathrin- and dynamin-independent, lipid raft-dependent pathway for homologous G protein-coupled receptor internalization.

scholarly journals Drebrin 1 in dendritic cells regulates phagocytosis and cell surface receptor expression through recycling for efficient antigen presentation

Immunology ◽  
2018 ◽  
Vol 156 (2) ◽  
pp. 136-146 ◽  
Author(s):  
Diana M. Elizondo ◽  
Temesgen E. Andargie ◽  
Naomi L. Haddock ◽  
Thomas A. Boddie ◽  
Michael W. Lipscomb
Keyword(s):  
Dendritic Cells ◽  
Cell Surface ◽  
Antigen Presentation ◽  
Receptor Expression ◽  
Cell Surface Receptor ◽  
Surface Receptor

scholarly journals The luminescent HiBiT peptide enables selective quantitation of G protein–coupled receptor ligand engagement and internalization in living cells

2020 ◽  
Vol 295 (15) ◽  
pp. 5124-5135 ◽  
Author(s):  
Michelle E. Boursier ◽  
Sergiy Levin ◽  
Kris Zimmerman ◽  
Thomas Machleidt ◽  
Robin Hurst ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Cell Surface ◽  
G Protein ◽  
Dynamic Range ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Receptor Internalization ◽  
Cell Surface Receptor ◽  
Cellular Interactions ◽  
G Protein Coupled

G protein–coupled receptors (GPCRs) are prominent targets to new therapeutics for a range of diseases. Comprehensive assessments of their cellular interactions with bioactive compounds, particularly in a kinetic format, are imperative to the development of drugs with improved efficacy. Hence, we developed complementary cellular assays that enable equilibrium and real-time analyses of GPCR ligand engagement and consequent activation, measured as receptor internalization. These assays utilize GPCRs genetically fused to an N-terminal HiBiT peptide (1.3 kDa), which produces bright luminescence upon high-affinity complementation with LgBiT, an 18-kDa subunit derived from NanoLuc. The cell impermeability of LgBiT limits signal detection to the cell surface and enables measurements of ligand-induced internalization through changes in cell-surface receptor density. In addition, bioluminescent resonance energy transfer is used to quantify dynamic interactions between ligands and their cognate HiBiT-tagged GPCRs through competitive binding with fluorescent tracers. The sensitivity and dynamic range of these assays benefit from the specificity of bioluminescent resonance energy transfer and the high signal intensity of HiBiT/LgBiT without background luminescence from receptors present in intracellular compartments. These features allow analyses of challenging interactions having low selectivity or affinity and enable studies using endogenously tagged receptors. Using the β-adrenergic receptor family as a model, we demonstrate the versatility of these assays by utilizing the same HiBiT construct in analyses of multiple aspects of GPCR pharmacology. We anticipate that this combination of target engagement and proximal functional readout will prove useful to the study of other GPCR families and the development of new therapeutics.

Increased cell-surface receptor expression on U-937 cells induced by 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine

2000 ◽  
Vol 48 (10) ◽  
pp. 569-578 ◽  
Author(s):  
Marina Y. Pushkareva ◽  
Sharon L. Wannberg ◽  
Andrew S. Janoff ◽  
Eric Mayhew
Keyword(s):  
Cell Surface ◽  
Receptor Expression ◽  
Cell Surface Receptor ◽  
Surface Receptor
Sign in / Sign up

Export Citation Format

Share Document