title: Structural changes of the ligand and of the receptor alters the receptor preference for neutrophil activating peptides starting with a formylmethionyl group.
abstract: Pathogenic Staphylococcus aureus strains produce N-formylmethionyl containing peptides, of which the tetrapeptide fMIFL is a potent activator of the neutrophil formyl peptide receptor 1 (FPR1) and the PSMα2 peptide is a potent activator of the closely related FPR2. Variants derived from these two peptide activators were used to disclose the structural determinants for receptor interaction. Removal of five amino acids from the C-terminus of PSMα2 gave rise to a peptide that had lost the receptor-independent neutrophil permeabilizing effect, whereas neutrophil activation capacity as well as its preference for FPR2 was retained. Shorter peptides, PSMα21-10 and PSMα21-5, activate neutrophils, but the receptor preference for these peptides was switched to FPR1. The fMIFL-PSM5-16 peptide, in which the N-terminus of PSMα21-16 was replaced by the sequence fMIFL, was a dual agonist for FPR1/FPR2, whereas fMIFL-PSM5-10 preferred FPR1 to FPR2. Further, an Ile residue was identified as a key determinant for interaction with FPR2. A chimeric receptor in which the cytoplasmic tail of FPR1 was replaced by the corresponding part of FPR2 lost the ability to recognize FPR1 agonists, but gained function in relation to FPR2 agonists. Taken together, our data demonstrate that the C-terminus of the PSMα2 peptide plays a critical role for its cytotoxicity, but is not essential for the receptor-mediated pro-inflammatory activity. More importantly, we show that the amino acids present in the C-terminus, which are not supposed to occupy the agonist-binding pocket in the FPRs, are of importance for the choice of receptor.
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Sweden.
authors.forename: Huamei
authors.initials: H
authors.lastname: Forsman
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Sweden.
authors.forename: Malene
authors.initials: M
authors.lastname: Winther
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Gabl
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Sweden; Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
authors.forename: Sarah Line
authors.initials: SL
authors.lastname: Skovbakke
authors.affiliation: Commissariat à l'Energie Atomique, DSV/IRTSV/Biology of Cancer and Infection, 38000 Grenoble, France; INSERM, U1036, Biology of Cancer and Infection, 38000 Grenoble, France; Université Grenoble-Alpes, 38000 Grenoble, France; CNRS, ERL5261, 38000 Grenoble, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Boulay
authors.affiliation: Commissariat à l'Energie Atomique, DSV/IRTSV/Biology of Cancer and Infection, 38000 Grenoble, France; INSERM, U1036, Biology of Cancer and Infection, 38000 Grenoble, France; Université Grenoble-Alpes, 38000 Grenoble, France; CNRS, ERL5261, 38000 Grenoble, France.
authors.forename: Marie-Josèphe
authors.initials: MJ
authors.lastname: Rabiet
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Sweden. Electronic address: Claes.Dahlgren@microbio.gu.se.
authors.forename: Claes
authors.initials: C
authors.lastname: Dahlgren
mesh_terms: D006801:Humans; D008024:Ligands; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology*; D018375:Neutrophil Activation / Q000187:drug effects*; D044042:Receptors, Formyl Peptide / Q000819:agonists / Q000737:chemistry* / Q000502:physiology; D044067:Receptors, Lipoxin / Q000819:agonists / Q000737:chemistry* / Q000502:physiology; D013329:Structure-Activity Relationship
chemical_list: C469986:FPR1 protein, human; C105101:FPR2 protein, human; D008024:Ligands; D044042:Receptors, Formyl Peptide; D044067:Receptors, Lipoxin; D009240:N-Formylmethionine Leucyl-Phenylalanine
keywords: Formyl peptide; G-protein coupled receptor; Inflammation; Neutrophil