Figure 2.

Different POLR3B de novo variants distinctively affect the assembly of specific RNA polymerase III subunits

(A–F) FLAG-tagged POLR3B wild type (WT), p.Asp375Val (A), p.Leu426Ser (B), p.Arg1064His (C), p.Ala365Val (D), p.Glu363Lys (E), and p.Thr462Arg (F) were expressed in HEK293 cells for 24 h, purified with an anti-FLAG antibody, and digested with trypsin. The co-purified proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The label-free quantification (LFQ) intensity of each peptide was computed via MaxQuant and Perseus. Volcano plots illustrate the log₂-transformed average LFQ-intensity difference between mutant and WT (x axis), and the –log₁₀ p value obtained via a two-tailed t test adjusted with a permutation-based multiple hypothesis testing with 10,000 iterations and an s0 correction factor of 0.1 (y axis). Proteins marked in red are considered significantly different between the conditions.