Related Experiment Video
Updated: Jun 23, 2026
09:03
Parallel Interrogation of β-Arrestin2 Recruitment for Ligand Screening on a GPCR-Wide Scale using PRESTO-Tango Assay
Published on: March 10, 2020
Membrane-tethered ligands are effective probes for exploring class B1 G protein-coupled receptor function
Jean-Philippe Fortin1, Yuantee Zhu, Charles Choi
1Molecular Pharmacology Research Center, Molecular Cardiology Research Institute, Tufts University School of Medicine, Boston, MA 02111, USA.
Summary
Researchers developed membrane-tethered peptides to modulate G protein-coupled receptors (GPCRs), offering new tools to study receptor function and biological roles.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Class B1 G protein-coupled receptors (GPCRs) regulate critical physiological processes like glucose homeostasis and feeding behavior.
- These receptors are activated by intermediate-length peptide ligands with distinct affinity and activation domains.
- Understanding GPCR signaling is crucial for developing targeted therapeutics.
Purpose of the Study:
- To develop a novel technology for selectively modulating class B1 GPCRs using membrane-tethered peptide ligands.
- To investigate the structure-function relationships of tethered ligands and their interaction with GPCRs.
- To create new tools for dissecting the in vivo biological roles of GPCRs.
Main Methods:
- Engineered cDNA constructs encoding single proteins with a transmembrane domain, linker, and tethered ligand.
- Demonstrated dose-dependent receptor activation by membrane-tethered peptides, similar to soluble ligands.
- Conducted mutational studies on incretin ligands, particularly for the glucagon-like peptide-1 receptor.
Main Results:
- Successfully developed and validated membrane-tethered peptides as functional modulators of class B1 GPCRs.
- Identified the N-terminal domain of peptide hormones as critical for tethered ligand activity.
- Showed that point mutations can convert tethered agonists into antagonists, enabling complementary modulation.
Conclusions:
- Membrane-tethered peptides represent a versatile technology for precise GPCR signaling modulation.
- These tools facilitate the study of GPCR structure-function relationships and tissue-specific roles.
- The ability to interconvert agonists and antagonists offers new avenues for pharmacological intervention and research.
Related Concept Videos
01:15G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
01:15G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
01:21G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
01:21G-protein Coupled Receptors
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
01:30Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...
01:22Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...