Co-translational assembly orchestrates competing biogenesis pathways

The biogenesis of nuclear pores imposes a logistic challenge for cells. Here, the authors investigate structural motifs for co-translational interactions in nucleoporins and find that co-translational assembly events differ between paralogous assembly pathways thus contributing to faithful assembly. During the co-translational assembly of protein complexes, a fully synthesized subunit engages with the nascent chain of a newly synthesized interaction partner. Such events are thought to contribute to productive assembly, but their exact physiological relevance remains underexplored. Here, we examine structural motifs contained in nucleoporins for their potential to facilitate co-translational assembly. We experimentally test candidate structural motifs and identify several previously unknown co-translational interactions. We demonstrate by selective ribosome profiling that domain invasion motifs of beta-propellers, coiled-coils, and short linear motifs may act as co-translational assembly domains. Such motifs are often contained in proteins that are members of multiple complexes (moonlighters) and engage with closely related paralogs. Surprisingly, moonlighters and paralogs assemble co-translationally in only some but not all of the relevant biogenesis pathways. Our results highlight the regulatory complexity of assembly pathways.

Automated summary

The authors investigate the structural motifs involved in co-translational assembly in nucleoporins and find that different paralogous assembly pathways have distinct co-translational assembly events. They identify several previously unknown co-translational interactions and demonstrate that domain invasion motifs of beta-propellers, coiled-coils, and short linear motifs may act as co-translational assembly domains. These findings highlight the regulatory complexity of assembly pathways.