||Budding yeast Saccharomyces cerevisiae
||Duttler S, Pechmann S, Frydman J. Principles of cotranslational ubiquitination and quality control at the ribosome. Mol Cell. 2013 May 9 50(3):379-93. doi: 10.1016/j.molcel.2013.03.010. p.391 left column top paragraphPubMed ID23583075
||S.J. Russell, K.A. Steger, S.A. Johnston, Subcellular localization, stoichiometry, and protein levels of 26 S proteasome subunits in yeast, J. Biol. Chem., 274 (1999), pp. 21943–21952 AND T. von der Haar, A quantitative estimation of the global translational activity in logarithmically growing yeast cells, BMC Syst. Biol., 2 (2008), p. 87 doi: 10.1186/1752-0509-2-87.PubMed ID10419517, 18925958
||P.391 left column top paragraph: "Biological Impact of Cotranslational Ubiquitination on Cellular Homeostasis: It is interesting to consider the impact of the low levels of cotranslational ubiquitination on overall cellular homeostasis. Ribosomes are present in 10-fold excess over proteasomes in both yeast and mammalian cells (primary sources), and, thus, a steady flow of 2%–5% of ubiquitinated nascent chains represents a substantial burden for the proteasome pathway, even under nonstressed conditions, particularly because proteasomal degradation has similar processivity rates as translation (Henderson et al., 2011). This consideration may reconcile the seemingly contradictory observations that de novo folding is favored over degradation (Frydman and Hartl, 1996, Vabulas and Hartl, 2005) with findings that newly made proteins contribute significantly to proteasomal load (Kim et al., 2011) and to antigen presentation (Lelouard et al., 2004, Reits et al., 2000)."