Acylation of the incretin peptide exendin-4 directly impacts glucagon-like peptide-1 receptor signaling and traffickings

Lucey, Maria; Ashik, Tanyel; Marzook, Amaara; Wang, Yifan; Goulding, Jöelle; Oishi, Atsuro; Broichhagen, Johannes; Hodson, David J.; Minnion, James; Elani, Yuval; Jockers, Ralf; Briddon, Stephen J.; Bloom, Stephen R.; Tomas, Alejandra; Jones, Ben

Abstract

The glucagon-like peptide-1 receptor (GLP-1R) is a class B G protein- coupled receptor and mainstay therapeutic target for the treatment of type 2 diabetes and obesity. Recent reports have highlighted how biased agonism at the GLP-1R affects sustained glucose-stimulated insulin secretion through avoidance of desensitization and downregulation. A number of GLP-1R agonists (GLP-1RAs) feature a fatty acid moiety to prolong their pharmacokinetics via increased albumin binding, but the potential for these chemical changes to influence GLP-1R function has rarely been investigated beyond potency assessments for cAMP. Here, we directly compare the prototypical GLP-1RA exendin-4 with its Cterminally acylated analog, exendin-4-C16. We examine relative propensities of each ligand to recruit and activate G proteins and b-arrestins, endocytic and postendocytic trafficking profiles, and interactions with model and cellular membranes in HEK293 and HEK293T cells. Both ligands had similar cAMP potency, but exendin- 4-C16 showed ∼2.5-fold bias toward G protein recruitment and a ∼60% reduction in b-arrestin-2 recruitment efficacy compared with exendin-4, as well as reduced GLP-1R endocytosis and preferential targeting toward recycling pathways. These effects were associated with reduced movement of the GLP-1R extracellular domain measured using a conformational biosensor approach and a ∼70%increase in insulin secretion in INS-1 832/3 cells. Interactions with plasma membrane lipids were enhanced by the acyl chain. Exendin-4-C16 showed extensive albumin binding and was highly effective for lowering of blood glucose in mice over at least 72 hours. Our study highlights the importance of a broad approach to the evaluation of GLP-1RA pharmacology.

Citation

Lucey, M., Ashik, T., Marzook, A., Wang, Y., Goulding, J., Oishi, A., Broichhagen, J., Hodson, D. J., Minnion, J., Elani, Y., Jockers, R., Briddon, S. J., Bloom, S. R., Tomas, A., & Jones, B. (2021). Acylation of the incretin peptide exendin-4 directly impacts glucagon-like peptide-1 receptor signaling and traffickings. Molecular Pharmacology, 100(4), 319-334. https://doi.org/10.1124/molpharm.121.000270

• Journal Article Type: Article
• Acceptance Date: Jul 14, 2021
• Online Publication Date: Oct 1, 2021
• Publication Date: 2021-10
• Deposit Date: Feb 20, 2025
• Publicly Available Date: Feb 20, 2025
• Journal: Molecular Pharmacology
• Print ISSN: 0026-895X
• Electronic ISSN: 1521-0111
• Publisher: American Society for Pharmacology and Experimental Therapeutics
• Peer Reviewed: Peer Reviewed
• Volume: 100
• Issue: 4
• Pages: 319-334
• DOI: https://doi.org/10.1124/molpharm.121.000270
• Public URL: https://nottingham-repository.worktribe.com/output/6615190
• Publisher URL: https://molpharm.aspetjournals.org/article/S0026-895X(24)01161-1/fulltext
• Additional Information: This article is maintained by: Elsevier; Article Title: Acylation of the Incretin Peptide Exendin-4 Directly Impacts Glucagon-Like Peptide-1 Receptor Signaling and Trafficking; Journal Title: Molecular Pharmacology; CrossRef DOI link to publisher maintained version: https://doi.org/10.1124/molpharm.121.000270; Content Type: article; Copyright: © 2021 The Author(s)