Furthermore, we show that complexes flip essentiality in a cohesive fashion between the two species, that is, they tend to change from mostly essential to mostly nonessential, or vice versa, but not to mixed patterns.
Furthermore, we show that complexes flip essentiality between the two species in a cohesive fashion, that is, they change from mostly essential to mostly nonessential or vice versa and that these flips can be associated with larger scale biological differences between the two yeasts.
In the budding yeast Saccharomyces cerevisiae, the subunits of any given protein complex are either mostly essential or mostly nonessential, suggesting that essentiality is a property of molecular machines rather than individual components.
Similarly, others have shown that essential genes are concentrated into specific complexes and that protein complexes are either mostly essential or mostly nonessential, suggesting that essentiality is a property of molecular machines rather than individual components (fig. 1 A) (Dezso et al. 2003; Hart et al. 2007; Semple et al. 2008; Wang et al. 2009).
The combination of genetic, cell biological, and proteomic methods has revealed that more than 200, mostly essential, non-ribosomal factors (also called biogenesis factors or protein trans-acting factors) contribute to eukaryotic ribosome biogenesis.
pombe complexes are disproportionately mostly essential or mostly nonessential (fig. 4 A), confirming that modular essentiality is conserved across species.
E-Cadherin in epithelial adherens junctions, Dsg-2 in desmosomes, β4 integrin in hemidesmosomes, CD44s in cell-matrix interactions, and ICAM-1 are, mostly, essential for tissue integrity, architecture, and function in normal salivary gland parenchyma.
We found, as in previous studies, that complexes are mostly essential or mostly nonessential, but that it is not an all or nothing phenomenon.
It has been demonstrated, using yeast co-expression networks, confirmed with knockout strain studies, that these network hubs are mostly essential genes [ 8, 9].
On the other hand, some ribosomal proteins (e.g., S16, L15, L16, L20, and L24) are mostly essential for the assembly of the RNP particle and are dispensable for function after the ribosomal subunits are fully assembled, suggesting that their major function in the assembled ribosome is related to the improvement of the ribosome stability.
About 70% of the metabolites have zero flux-sum in the base case while metabolites with high and ultra-high ((1) ) basal flux-sums were mostly essential cofactors that are involved in oxidative phosphorylation and redox reactions with a high degree of participation in basal active reactions (i.e. reactions with nonzero basal flux).
