Fig. 2: Transcription errors result in proteins with increased amyloid-like behavior.
From: Transcript errors generate amyloid-like proteins in human cells
A A transcription error (Tr) was identified in the SOD1 transcript that mimics a mutation (Mut) implicated in ALS. This error substitutes a guanine for an adenine base, resulting in a glycine (G) to glutamine (E) mutation at residue 142. B WT SOD1 is soluble and present throughout the cell, including the nucleus. C In contrast, SOD1G142E proteins form aggregates and are excluded from the nucleus. D Quantification of WT and mutant SOD1 aggregation and mislocalization. Depicted are the % of cells with aggregates or mislocalized proteins (n = 3 biological replicates). For aggregates, P = 0.0015, for mislocalization, P = 0.0102. E A transcription error was identified in the FUS transcript that mimics a mutation implicated in ALS. This error substituted a guanine for an adenine base, resulting in an arginine (R) to histidine (H) mutation at residue 521. F WT FUS is present in a soluble state in the nucleus, while FUSR521H (G) forms aggregates outside of the nucleus. H Quantification of FUS aggregation and mislocalization (n = 3 biological replicates). Depicted are the % of cells with aggregates or mislocalized proteins. For aggregates, P = 0.0108, for mislocalization, P = 0.0174. I, J Transfection of cells with 500 ng of SOD1G142E mRNA resulted in cells with clearly visible mislocalized protein aggregates (n = 3 biological replicates). K–M When cells are transducted with lentiviral particles carrying both WT SOD1 and SOD1G142E simultaneously, WT SOD1 is excluded from the nucleus and recruited into extranuclear aggregates. N Quantification of SOD1 colocalization with either N-terminal or C-terminal tags. O–Q WT and FUSR521H co-expression in primary human fibroblasts, demonstrating that mutant and WT FUS co-localize in cytoplasmic aggregates (n = 3 biological replicates). R Quantification of FUS colocalization with either N-terminal or C-terminal tags. (n = 3 biological replicates). S WT SOD1 does not form fibers under TEM, but SOD1G142E does (T). TEM experiments were performed 3 times with similar results. *P < 0.05. **P < 0.01 according to a two-tailed unpaired t-test with Welch’s correction. Data are presented as mean values ± SEM. Source data are provided as a Source Data file.
