Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
FEMS Yeast Res. 2012 Mar;12(2):118-28. doi: 10.1111/j.1567-1364.2011.00767.x. Epub 2011 Dec 19.
The yeast Saccharomyces cerevisiae can show different metabolic phenotypes (e.g. fermentation and respiration). Based on data from the literature, we argue that the substrate uptake rate is the core variable in the system that controls the global metabolic phenotype. Consequently the metabolic phenotype that the cell expresses is not dependent on the type of the sugar or its concentration, but only on the rate at which the sugar enters the cell. As this requires the cells to 'measure' metabolic flux, we discuss the existing clues toward a flux-sensing mechanism in this organism and also outline several aspects of the involved flux-dependent regulation system. It becomes clear that the sensing and regulation system that divides the taken up carbon flux into the respiratory or fermentative pathways is complex with many molecular components interacting on multiple levels. To obtain a true understanding about how the global metabolic phenotype of S. cerevisiae is controlled by the glucose uptake rate, different tools and approaches from systems biology will be required.
酵母酿酒酵母可以表现出不同的代谢表型（例如发酵和呼吸）。基于文献中的数据，我们认为底物摄取率是控制全局代谢表型的系统中的核心变量。因此，细胞表达的代谢表型不依赖于糖的类型或其浓度，而仅取决于糖进入细胞的速度。由于这需要细胞“测量”代谢通量，我们讨论了该生物体中存在的通量感应机制的线索，并概述了所涉及的通量依赖性调节系统的几个方面。很明显，将吸收的碳通量分配到呼吸或发酵途径的感应和调节系统很复杂，许多分子成分在多个层面上相互作用。要真正了解葡萄糖摄取率如何控制酿酒酵母的全局代谢表型，需要从系统生物学中使用不同的工具和方法。
