GSE118676
Stoichiometric Production of Protein-Complex Components in Eukaryotes Without Widespread Feedback Regulation
Constituents of multi-protein complexes are required at well-defined levels relative to each other. However, it remains unknown whether eukaryotic cells typically produce precise amounts of subunits, or instead rely on degradation to mitigate imprecise production. Here we quantified the production rates of multi-protein complexes in single- and multi-cellular eukaryotes using ribosome profiling. By resolving read-mapping ambiguities present in a large fraction of ribosome footprints which often distorts quantitation accuracy in eukaryotes, we found that obligate components of multi-protein complexes are produced in proportion to their stoichiometry, indicating that their abundances are already precisely tuned at the synthesis level. By systematically interrogating the impact of gene dosage variations in budding yeast, we found a general lack of negative feedback regulation protecting the normally precise rates of subunit synthesis. These results reveal a core principle of proteome homeostasis and highlight the evolution towards quantitative control at every stage of the central dogma. Overall design: 13 ribosome profiling experiments in Saccharomyces cerevisiae