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bioRxiv · 10.1101/005553

Differential stoichiometry among core ribosomal proteins

Nikolai Slavov·Stefan Semrau·Edoardo Airoldi·Bogdan Budnik·Alexander van Oudenaarden
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Abstract

Understanding the regulation and structure of ribosomes is essential to understanding protein synthesis and its dysregulation in disease. While ribosomes are believed to have a fixed stoichiometry among their core ribosomal proteins (RPs), some experiments suggest a more variable composition. Testing such variability requires direct and precise quantification of RPs. We used mass-spectrometry to directly quantify RPs across monosomes and polysomes of mouse embryonic stem cells (ESC) and budding yeast. Our data show that the stoichiometry among core RPs in wild-type yeast cells and ESC depends both on the growth conditions and on the number of ribosomes bound per mRNA. Furthermore, we find that the fitness of cells with a deleted RP-gene is inversely proportional to the enrichment of the corresponding RP in polysomes. Together, our findings support the existence of ribosomes with distinct protein composition and physiological function.

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Nikolai Slavov, Stefan Semrau, Edoardo Airoldi, Bogdan Budnik, Alexander van Oudenaarden. 2014-05-26. Differential stoichiometry among core ribosomal proteins. https://doi.org/10.1101/005553

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