Department of Biology and Biological Engineering, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Nat Commun. 2020 Apr 20;11(1):1881. doi: 10.1038/s41467-020-15749-0.
Cells maintain reserves in their metabolic and translational capacities as a strategy to quickly respond to changing environments. Here we quantify these reserves by stepwise reducing nitrogen availability in yeast steady-state chemostat cultures, imposing severe restrictions on total cellular protein and transcript content. Combining multi-omics analysis with metabolic modeling, we find that seven metabolic superpathways maintain >50% metabolic capacity in reserve, with glucose metabolism maintaining >80% reserve capacity. Cells maintain >50% reserve in translational capacity for 2490 out of 3361 expressed genes (74%), with a disproportionately large reserve dedicated to translating metabolic proteins. Finally, ribosome reserves contain up to 30% sub-stoichiometric ribosomal proteins, with activation of reserve translational capacity associated with selective upregulation of 17 ribosomal proteins. Together, our dataset provides a quantitative link between yeast physiology and cellular economics, which could be leveraged in future cell engineering through targeted proteome streamlining.
细胞通过维持代谢和翻译能力的储备作为一种策略，以快速应对不断变化的环境。在这里，我们通过逐步降低酵母恒化培养物中氮的可用性来量化这些储备，从而对总细胞蛋白和转录物含量施加严格限制。通过将多组学分析与代谢建模相结合，我们发现七种代谢超级途径保持了>50%的储备代谢能力，其中葡萄糖代谢保持了>80%的储备能力。对于 3361 个表达基因中的 2490 个（74%），细胞在翻译能力方面保持了>50%的储备，其中大量的储备专门用于翻译代谢蛋白。最后，核糖体储备中含有高达 30%的亚化学计量核糖体蛋白，储备翻译能力的激活与 17 种核糖体蛋白的选择性上调相关。总的来说，我们的数据集为酵母生理学和细胞经济学之间提供了定量联系，这可以通过靶向蛋白质组简化在未来的细胞工程中得到利用。
