Fig 2.

The MALAR-Y2H identified neuropeptide interaction partners of SmGPCR20. Shown are cell-growth assays of the yeast strain AH109 transfected with plasmids expressing the ligand fusion proteins (40). These cells were mated with yeast strain Y187, which had been transfected with a plasmid expressing SmGPCR20 as fusion protein. The Trp⁻, Leu⁻ control (right panel) indicated the successful transformation of yeast cells with all used plasmids. Trp⁻, Leu⁻, His⁻, and Ade⁻ (left panel) showed growth under selection conditions for protein interaction, in this case with the candidate neuropeptides L26 and L40 (a, b, c, and d indicate different fragments of SmNPP26 and SmNPP40). The chemokine CXCL12 and its known receptor CXCR4 were employed as positive control. OST1 is a transmembrane protein of S. cerevisiae and, in combination with CXCL12, used as the negative control (39).