Fig. 5.

[L⁸]-chemerin-9 is a selective ligand for GPR1 in arrestin3 recruitment assays. Stimulating GPR1 with chemerin-9 demonstrates a high potency of the peptide to recruit arrestin3 in a BRET assay (EC₅₀ = 1.9 nM). [L⁸]-chemerin-9 displays identical activity (EC₅₀ = 1.4 nM). Stimulating CMKLR1 with increasing concentrations of chemerin-9 displays nanomolar activity of the peptide (EC₅₀ = 44 nM), [L⁸]-chemerin-9 does not trigger recruitment of arrestin3 to the receptor. Data points represent mean ± SEM from at least two independent experiments performed in quadruplicates. Data were normalized to the top and bottom values of the respective chemerin-9 curve