A peptide display system identifies a potent mutant β-melanocyte-stimulating hormone agonist of melanocortin-4 receptor

  • Cell Genom. 2025 Sep 9:100988. doi: 10.1016/j.xgen.2025.100988.
Ann Lin  1 ,  Kaitlyn Spees  1 ,  Raeline Valbuena  1 ,  Jakob Wirbel  2 ,  Aravind Natarajan  2 ,  Nora Enright  3 ,  Ami S Bhatt  4 ,  Michael C Bassik  5
Affiliations
  • 1. Department of Genetics, Stanford University, Stanford, CA, USA.
  • 2. Department of Medicine, Division of Hematology, Stanford University, Stanford, CA, USA.
  • 3. Department of Bioengineering, Stanford University, Stanford, CA, USA.
  • 4. Department of Genetics, Stanford University, Stanford, CA, USA; Department of Medicine, Division of Hematology, Stanford University, Stanford, CA, USA. Electronic address: [email protected].
  • 5. Department of Genetics, Stanford University, Stanford, CA, USA. Electronic address: [email protected].
PMID: 40930102 DOI: 10.1016/j.xgen.2025.100988
Abstract

Non-olfactory G-protein-coupled receptors (GPCRs) regulate vital physiological functions and are targets for ∼34% of US Food and Drug Administration (FDA)-approved drugs. While small-molecule-activated GPCRs are well studied, there is growing interest in peptide GPCRs, particularly the melanocortin-4 receptor (MC4R), a key regulator of energy balance and appetite. Activation of MC4R by β-melanocyte-stimulating hormone (β-MSH) reduces food intake, and pathway dysfunction leads to obesity. However, current methods to study GPCR-peptide interactions are resource intensive and low throughput. To address this, we developed a high-throughput cell surface peptide display platform with a β-arrestin-based MC4R reporter to screen over 2,000 β-MSH point mutants. This approach identified peptide variants that significantly impact MC4R activation, including a novel D5H mutant with enhanced receptor activation. Our results demonstrate a scalable method to directly link GPCR activation to peptide variants, offering insights for therapeutic peptide design.

Keywords
MC4R; peptide display; scanning mutagenesis.
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