Fig. 1. SeRP of importins reveals co-translational binding to cargo.

a Scheme illustrating the co-translational binding of importins to a nascent chain. b Pearson correlation of the area under curve (AUC)-values of the selective ribosome enrichment profiles (IP/total) of 5855 genes quantified across the experiments. c Same as (b) but for the 71 manually curated cargoes. d Visualization of the Gene Ontology (GO)-enrichment for cellular compartments. While Srp1-Kap95 enriches chromosomal and telomeric regions, Kap123 shows enrichment for the nucleolus. Only significantly enriched GO-terms are shown (P-value < 0.1, not adjusted, (two-sided) Fisher Exact Test relative to all proteins quantified). e Same as (d) but for biological function. While Kap123 enriches for rRNA processing, cytoplasmic translation, and translation termination, Srp1-Kap95 rather enriches for cell division, DNA repair, and transcription regulation. f Representative SeRP profiles. In most cases, importins associate with the nascent chain and subsequently remain bound, whereas Efr3 (Sxm1-SeRP) constitutes an exception. SeRP profiles (IP/total) are shown for the respective mRNA targets from n = 4 biologically independent replicates (solid lines are averaged across replicates; shades reflect largest to smalls replicate value interval). Gray dashed lines indicate an arbitrary threshold of 2 used for onset estimation (red dashed line). Note, that in the case of nab2-mRNA, a threshold of 1.5 was chosen. Domain annotation based on Pfam. transcr. transcription, RNA-pol. II RNA-polymerase II, IP immunoprecipitation, AA amino acid, DBD DNA binding domain, ATP ATP helicase domain, CTD C-terminal domain, NTM N-terminal motif, QQQP glutamine-rich region, RGG arginine-glycine-glycine domain, C3H1-type ZnF cysteine-cysteine-cysteine-histidine-type zinc finger domain, PH Pleckstrin homology domain, TM transmembrane domain.