Fig. 1: Comprehensive unbiased screen reveals GRM4 and NPDC1 as novel PFF-interactors.

a Schematic representation of the screening process. Briefly, HEK293T were plated in 96-well plates. A total of 4,401 cDNAs were used individually to transfect the cells. Two days after transfection, cells were treated with biotinylated α-syn PFF (1000 nM, monomer equivalents) for 2 h at RT and bound α-syn assessed. The micrograph shows that there was no detectable binding to control HEK293T cells. As a result, 16 membrane proteins were confirmed as PFF interactors. b Representative images of HEK293T cells transfected with GRM4 (upper panels) and NPDC1 (lower panels) treated with biotinylated α-syn PFF (1000 nM) for 2 h and stained for α-syn PFF binding (streptavidin, gray) and GRM4 or NPDC1 expression (V5 tag, green). Scale bar, 100 µm. c Graphs show mean ± SEM of the mean intensity of streptavidin (PFF) at different concentrations of α-syn PFF in HEK293T cells transfected with GRM4 or NPDC1. N = 3 independent experiments. d Graphs show mean ± SEM of the mean intensity of streptavidin (PFF) bound to HEK293T cells transfected with GRM4 (upper graph) and NPDC1 (lower graph) after exposure to 3000 nM α-syn monomer or PFF for cell transfected with GRM4 (upper graph) and NPDC1 (lower graph). N = 4 independent experiments.**p = 0.002 for GRM4, ***p = 0.0004 for NPDC1, two tailed t test.