The Synthetic Peptide Trp-Lys-Tyr-Met-Val-d-Met Is a Potent Chemotactic Agonist for Mouse Formyl Peptide Receptor

Abstract

Formyl peptides are potent neutrophil chemoattractants. In humans and rabbits, the formyl peptide receptor (FPR) binds N-formyl-Met-Leu-Phe (fMLF) with high affinity (Kd ≈ 1 nM). The mouse FPR (mFPR) is a low-affinity receptor for fMLF (Kd ≈ 100 nM); therefore, other agonists for this receptor may exist. Using mFPR-transfected rat basophilic leukemia cells, we found that a recently identified synthetic peptide Trp-Lys-Tyr-Met-Val-d-Met (WKYMVm) is a potent agonist for mFPR. WKYMVm induced calcium mobilization with an EC50 of 1.2–1.5 nM. Optimal chemotaxis was achieved with 1 nM of WKYMVm, but it required 100 nM of fMLF. WKYMVm stimulated rapid and potent phosphorylation of the mitogen-activated protein kinases extracellular signal-related kinases 1 and 2 when used at 50 nM. Pertussis toxin only partially blocked calcium mobilization and production of inositol 1,4,5-trisphosphate in the stimulated mFPR cells, suggesting the possibility that this receptor couples to Gα proteins other than Gi and Go. Competitive binding and desensitization data suggest that both peptides interact with the same receptor but may use nonoverlapping binding sites because WKYMVm was unable to effectively displace [3H]fMLF bound to mFPR. These results provide evidence for the presence of an alternative potent agonist for mFPR, and suggest a potential usage of WKYMVm for probing the ligand-receptor interactions with the murine formyl peptide receptor homologs.

Junctional adhesion molecule-A-deficient polymorphonuclear cells show reduced diapedesis in peritonitis and heart ischemia-reperfusion injury

“…4b). As a chemotactic stimulus, we used the peptide WKYMVm, which is known to interact more effectively with the mouse fMLP receptor (25). Similarly to in vivo conditions, the presence or absence of JAM-A in endothelial cells did not change these parameters.…”

Trp-Lys-Tyr-Met-Val-Met stimulates phagocytosis via phospho-lipase D-dependent signaling in mouse dendritic cells

“…WKYMVm was reported to bind FPR, FPRL1, and FPRL2 in human leukocytes (Le et al, 1999;He et al, 2000;Christophe et al, 2001). The expression of mRNA for the different FPR family receptors in the DC2.4 cells was analyzed to identify different receptors by using semiquantitative RT-PCR analysis.…”

“…Initially, the expression of FPR family proteins in the DC2.4 cells was investigated by using [ 125 I]-labeled W KYMVm, a specific ligand for FPR family (FPR, FPRL1, and FPRL2) (Le et al, 1999;He et al, 2000;Christophe et al, 2001). The DC2.4 cells were incubated with various concentrations of [ 125 I]-labeled WKYMVm in the presence or absence of excess of the unlabeled WKYMVm, WKYMVM, or fMLF.…”

L-selectin is required for fMLP- but not C5a-induced margination of neutrophils in pulmonary circulation

“…fMLP is a low-affinity agonist for murine formyl peptide receptors (K d , ϳ100 nM), whereas human and rabbit formyl peptide receptors bind fMLP with much higher (K d , ϳ1 nM) affinity (18). The low dose of fMLP used in this study induces complete neutropenia in rabbits (34), as opposed to the 35% decrease in peripheral neutrophils in mice that we report here.…”