Supplementary Figure 2: Example genetic modifiers and specificity of the DPR screens compared with similar screens for ricin toxicity.

(a) Distribution of sequencing from 10 KCNK5 sgRNAs (blue) compared to distribution of sequencing counts of all negative control sgRNA (grey) from PR₂₀ screen replicate 1 (this is an example of a protective genetic modifier). (b) Distribution of sequencing from 10 RHOA sgRNAs (red) compared to distribution of sequencing counts of all negative control sgRNA (grey) from PR₂₀ screen replicate 1 (this is an example of a sensitizing genetic modifier). Using CasTLE these sgRNA count distributions were used to generate effect scores, confidence scores and p-values for each gene (see Supplementary Table 1). (c) Volcano plot of effect vs. confidence scores for all human genes in the PR₂₀ screen. Colored in blue are all the genes conferring resistance to PR₂₀ when knocked out (10%FDR) and colored in red are all the genes conferring sensitivity to PR₂₀ when knocked out (10% FDR). (d) Correlation of casTLE scores for all genes in the library in our screen for modifiers of PR20 toxicity compared to an independent screen for modifiers of another toxic protein, ricin performed in near identical conditions (same lab, same cell line, same sgRNA library). There was zero (R² = 0) overall correlation between the hits for each screen suggesting a high degree of specificity in the modifiers identified in each screen. Note that TMX2 was only identified as a hit in the PR screen and not the ricin screen.