Monoclonal Antibody 5F1 Modulates Formyl Peptide Receptor 1 Conformation for Transmembrane Signaling.

ABSTRACT: Formyl peptide receptor 1 (FPR1) is a G protein-coupled receptor (GPCR) that mediates chemotaxis and bactericidal activities in phagocytes. The monoclonal antibody 5F1 is generated against full-length FPR1 and used widely for detection of FPR1 expression. This study aimed to characterize 5F1 for its functions. We found that 5F1 is highly selective for human FPR1 over the homologous FPR2. Epitope mapping led to the identification of extracellular loop 2 (ECL2) as a major epitope, and the synthetic peptide of ECL2 interfered with 5F1 binding to FPR1. Using a NanoLuc Bioluminescence Resonance Energy Transfer approach, we found that 5F1 binding induced FPR1 conformational changes. Although less potent than fMLF, 5F1 binding induced FPR1 internalization, Gi protein dissociation, and β-arrestins

SUBMITTER: Wang Y 

PROVIDER: S-EPMC12415353 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature