Fig. 5
Identification of neuropeptides that act as ligands for A. rubens kisspeptin-type receptors. A ArKPR1 is only activated by ArKP1.2 (EC50 = 1.16 × 10−8 M). B ArKPR3 is only activated by ArKP2.2 (EC50 = 5.80 × 10−10 M). C ArKPR6 is activated by multiple neuropeptides at high concentrations (> 1 µM) but is only activated by a ‘cocktail’ of neuropeptides derived from the F-type SALMFamide precursor at lower concentrations (EC50 = 1.33 × 10−9 M). D ArKPR7 is activated by multiple neuropeptides at high concentrations (> 1 µM) but is only activated by a ‘cocktail’ of neuropeptides derived from the L-type SALMFamide precursor at lower concentrations (EC50 = 2.43 × 10−9 M). E ArKPR8 is activated by both ArKP1.1 and ArKP1.2 at high concentrations (> 1 µM) but is only activated by ArKP1.1 at lower concentrations (EC50 = 3.88 × 10−7 M). F ArKPR9 is activated by ArKP1.1, ArKP1.2, and a ‘cocktail’ of neuropeptides derived from the L-type SALMFamide precursor, but ArKP1.2 is the most potent ligand for this receptor (EC50 = 3.07 × 10−.8 M). Key: green = ArKP1.1; pink = ArKP1.2; purple = ArKP2.2; blue = ‘cocktail’ of neuropeptides derived from the L-type SALMFamide precursor (ArS1.1–7); red = ‘cocktail’ of neuropeptides derived from the F-type SALMFamide precursor (ArS2.1–8). Each point represents mean values (± S.E.M.) from at least four independent experiments, with each experiment performed in triplicate. Luminescence is expressed as a percentage of the maximal response observed in each experiment. The source data for these experiments is provided in Additional file 15