The Trypanosoma brucei RNA-binding protein DRBD18 ensures correct mRNA trans splicing and polyadenylation patterns

Proteins associated with DRBD18. (A) Volcano plot showing proteins that were significantly enriched with DRBD18-TAP relative to TAP-GFP. The x-axis shows log₂ enrichment, while the y-axis is −log₁₀ of the P-value generated by the Perseus algorithm (Tyanova et al. 2016). Proteins outside the curved lines are calculated to be significantly enriched according to the method described in Keilhauer et al. (2015), using a double-sided two sample t-test with permutation-based FDR of 0.01, and with parameter S₀ (for minimal fold change) set to 0.1. Spots for proteins that are mentioned in the text and showed specific enrichment with ZC3H18 are labeled; these were present in all three DRBD18 preparations, had P-values of less than 0.01, and were greater than fourfold enriched as calculated in Perseus. Spots that are not labeled include ribosomal proteins, abundant enzymes, and RNA processing factors. In addition, we have not labeled spots for proteins with anomalous enrichment values and probabilities due to the replacement, by the Perseus algorithm (Tyanova et al. 2016), of absent values (protein not detected) by random ones. For the DRBD18-GFP comparison, these include ALBA2, DRBD4, ZC3H41, and RBP42 and Nup109, all of which copurified with DRBD18 but not GFP. (B) Volcano plot showing proteins that were significantly enriched with DRBD18-TAP relative to TAP-ZC3H28. The data for ZC3H28 and GFP were described previously (Bishola Tshitenge and Clayton 2021). Details and color codes are as in panel A, except that some proteins that were selectively enriched with ZC3H28 are labeled.