Impact of secretin receptor homo-dimerization on natural ligand binding

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 23, 2024

Abstract Class B G protein-coupled receptors can form dimeric complexes important for high potency biological effects. Here, we apply pharmacological, biochemical, and biophysical techniques to cells membranes expressing the prototypic secretin receptor (SecR) gain insights into binding homo-dimeric monomeric SecR. Spatial proximity between peptide residues, probed by disulfide bond formation, demonstrates that N-terminus moves from adjacent extracellular loop 3 (ECL3) at wild type SecR toward ECL2 in non-dimerizing mutants. Analysis of fluorescent analogs stable engagement C-terminal region within domain (ECD) both receptors, while mid-region exhibits lower mobility docked monomer. Moreover, decoupling protein interaction reduces levels similar mutant, whereas it has no further impact on These data support a model whereby ability dimerize promotes higher conformational dynamics peptide-bound ECD ECLs likely facilitates more efficient recruitment activation, consistent with observed functional relative mutant receptor.

Language: Английский

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Isoquinoline small molecule ligands are agonists and probe-dependent allosteric modulators of the glucagon subfamily of GPCRs

Biochemical Pharmacology, Journal Year: 2024, Volume and Issue: 229, P. 116483 - 116483

Published: Aug. 13, 2024

Class B1 G protein-coupled receptors (GPCRs) are peptide hormone and well validated therapeutic targets, however development of non-peptide drugs targeting this class is challenging. Recently, a series isoquinoline-based derivates were reported in the patent literature as allosteric ligands for glucagon receptor subfamily, two compounds, LSN3451217 LSN3556672, used to facilitate structural studies with glucagon-like peptide-1 (GLP-1R) glucose dependent insulinotropic (GIPR) bound orthosteric agonists. Here we pharmacologically characterized stereoisomers across GPCR family. This revealed LSN3556672 isomers agonists (GCGR), GLP-1R, GIPR calcitonin (CTR), albeit degree agonism varied at each receptor. In contrast, more selective lower potency GCGR CTR no activity GIPR. All compounds also modulated peptide-mediated cyclic adenosine monophosphate (cAMP) signaling GIPR, lesser extent probe-dependent manner, modest positive modulation observed some peptides, negligible effects other peptides. contrast neutral or weak negative/positive was peptides assessed CTR. study expands our knowledge on may have implications future drug discovery efforts subfamily.

Language: Английский

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Distinct Activation Mechanisms of CXCR4 and ACKR3 Revealed by Single-Molecule Analysis of their Conformational Landscapes

Published: Aug. 21, 2024

The canonical chemokine receptor CXCR4 and atypical ACKR3 both respond to CXCL12 but induce different effector responses regulate cell migration. While couples G proteins directly promotes migration, is protein- independent scavenges extracellular levels maintain responsiveness, thereby indirectly influencing receptors also have distinct activation requirements. only responds wild-type sensitive mutation of the chemokine. By contrast, recruits GPCR kinases (GRKs) β-arrestins promiscuously CXCL12, variants, other peptides proteins, relatively insensitive mutation. To investigate role conformational dynamics in pharmacological behaviors ACKR3, we employed single-molecule FRET track discrete states real-time. data revealed that apo-CXCR4 preferentially populates a high- inactive state, while apo-ACKR3 shows little preference high transition probabilities among multiple inactive, intermediate active conformations, consistent with its propensity for activation. Multiple active-like conformations are populated response agonists, compared single active-state. This markedly landscapes suggest may be achieved by broader distribution than CXCR4. Much heterogeneity linked residue differs between dynamic properties underly inability form productive interactions would drive signaling.

Language: Английский

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Distinct Activation Mechanisms of CXCR4 and ACKR3 Revealed by Single-Molecule Analysis of their Conformational Landscapes

eLife, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 21, 2024

The canonical chemokine receptor CXCR4 and atypical ACKR3 both respond to CXCL12 but induce different effector responses regulate cell migration. While couples G proteins directly promotes migration, is G-protein-independent scavenges extracellular levels maintain responsiveness, thereby indirectly influencing receptors also have distinct activation requirements. only responds wild-type sensitive mutation of the chemokine. By contrast, recruits GPCR kinases (GRKs) β-arrestins promiscuously CXCL12, variants, other peptides proteins, relatively insensitive mutation. To investigate role conformational dynamics in pharmacological behaviors ACKR3, we employed single-molecule FRET track discrete states real-time. data revealed that apo-CXCR4 preferentially populates a high-FRET inactive state, while apo-ACKR3 shows little preference high transition probabilities among multiple inactive, intermediate active conformations, consistent with its propensity for activation. Multiple active-like conformations are populated response agonists, compared single active-state. This markedly landscapes suggest may be achieved by broader distribution than CXCR4. Much heterogeneity linked residue differs between dynamic properties underly inability form productive interactions would drive signaling.

Language: Английский

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MSA clustering enhances AF-Multimer's ability to predict conformational landscapes of protein-protein interactions

Bioinformatics Advances, Journal Year: 2024, Volume and Issue: 5(1)

Published: Dec. 6, 2024

Understanding the conformational landscape of protein-ligand interactions is critical for elucidating binding mechanisms that govern these interactions. Traditional methods like molecular dynamics (MD) simulations are computationally intensive, leading to a demand more efficient approaches. This study explores how multiple sequence alignment (MSA) clustering enhance AF-Multimer's ability predict landscapes, particularly proteins with states.

Language: Английский

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