Fig. 1

BioID of poly-GA, -GR, and -PR shows specific proximity labeling of DPR protein aggregates. A myc-BioID-tagged poly-GA, -GR, and -PR fusion proteins expressed in HEK293T cells form distinct aggregates (anti-myc; green) that are strongly labeled with biotin (neutravidin; magenta). EGFP-transfected cells were used as a negative control, while the myc-BioID expressing specificity control shows general nucleocytoplasmic labeling (Scale bar = 5 µm). B Affinity purification experiments with streptavidin beads show the enrichment of distinct biotinylated proteins in the pull-down fraction. Anti-β-tubulin was used as a loading control. C Silver staining shows affinity purified biotinylated proteins with low levels of endogenously biotinylated and unspecifically binding proteins in the negative control (EGFP)