Fig. 6.

Features of RNA-interacting proteins found by PTex. a Top 3 enriched GO terms (CC, MF, BP) and b enriched protein domains in PTex-purified proteins from HEK293 cells; p-value derived from a one-tail Fisher Exact test and FDR determined by the Benjamini–Hochberg method⁷⁵. c PTex-purified proteins overlap with well-described RBPs but not transcription factors. Recovery of Gerstberger RBPs and transcripiton factors (TFs) reviewed in ref. ²⁹, a recent review on RBPs by ref. ⁸, HEK293 poly-A binders², RBPs found by RNA interactome using click chemistry (RICK;¹² CARIC¹³), P-body components³⁹ and a recent prediction of candidate RBPs (SONAR⁴⁰,). d Distribution of previously identified HEK293 mRNA-binding proteins (green;²) in PTex; each bin represents 10% of the 3037 PTex proteins from lowest to highest enrichment. e mRNA-binding proteins display a bimodal pI distribution pattern with peaks at pH 5.5 and 9.5^{1, 2}. RNA-interactors in general peak at pI 5–6 as found by PTex and RICK¹². Proteins of the RNA exosome are prototype PTex proteins. f The RNA exosome core consists of 10 subunits: nine non-catalytically active proteins (Exo-9) forming a barrel-like structure and an additional RNase (Rrp44; Exo-10); modified from ref. ⁴¹. g *All exosome subunits are labelled “RNA-binding” (Uniprot.org); **green = identified via poly-A selection in ref. 2; orange = enriched in PTex