Chapman Stephen P, Trindade Dos Santos Marcelo, Johnson Giles N, Kritz Mauricio Vieira, Schwartz Jean-Marc
Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK; School of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PT, UK; Current address: Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerrddan, Aberystwyth, SY23 3EE, UK.
Laboratório Nacional de Computação Científica, Petrópolis, RJ, 25651-075, Brazil.
Biosystems. 2017 Dec;162:119-127. doi: 10.1016/j.biosystems.2017.09.014. Epub 2017 Sep 29.
The regulation of metabolic networks has been shown to be distributed and shared through the action of metabolic cycles. Biochemical cycles play important roles in maintaining flux and substrate availability for multiple pathways to supply cellular energy and contribute to dynamic stability. By understanding the cyclic and acyclic flows of matter through a network, we are closer to understanding how complex dynamic systems distribute flux along interconnected pathways. In this work, we have applied a cycle decomposition algorithm to a genome-scale metabolic model of Chlamydomonas reinhardtii to analyse how acetate supply affects the distribution of fluxes that sustain cellular activity. We examined the role of metabolic cycles which explain the down regulation of photosynthesis that is observed when cells are grown in the presence of acetate. Our results suggest that acetate modulates changes in global metabolism, with the pentose phosphate pathway, the Calvin-Benson cycle and mitochondrial respiration activity being affected whilst reducing photosynthesis. These results show how the decomposition of metabolic flux into cyclic and acyclic components helps to understand the impact of metabolic cycling on organismal behaviour at the genome scale.
代谢网络的调控已被证明是通过代谢循环的作用进行分布和共享的。生化循环在维持通量以及为多种途径提供底物可用性以供应细胞能量并促进动态稳定性方面发挥着重要作用。通过了解物质在网络中的循环和非循环流动，我们更接近于理解复杂动态系统如何沿着相互连接的途径分配通量。在这项工作中，我们将一种循环分解算法应用于莱茵衣藻的基因组规模代谢模型，以分析乙酸盐供应如何影响维持细胞活性的通量分布。我们研究了代谢循环的作用，这些循环解释了在乙酸盐存在下细胞生长时观察到的光合作用下调现象。我们的结果表明，乙酸盐调节全局代谢变化，磷酸戊糖途径、卡尔文 - 本森循环和线粒体呼吸活性受到影响，同时光合作用降低。这些结果表明，将代谢通量分解为循环和非循环成分有助于在基因组规模上理解代谢循环对生物体行为的影响。
