Effects of microcompartmentation on flux distribution and metabolic pools in Chlamydomonas reinhardtii chloroplasts.
Effects of microcompartmentation on flux distribution and metabolic pools in Chlamydomonas reinhardtii chloroplasts.
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DOI：
10.7554/elife.37960
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发表时间：
2018-10-11
期刊：
影响因子：
7.7
通讯作者：
Mettler-Altmann T
中科院分区：
文献类型：
--
作者：
Küken A;Sommer F;Yaneva-Roder L;Mackinder LC;Höhne M;Geimer S;Jonikas MC;Schroda M;Stitt M;Nikoloski Z;Mettler-Altmann T
细胞和细胞器是不均匀的，但包括改变细胞过程的时空特征的微区室。然而，微区室化对代谢途径的影响很难通过实验研究。蛋白核是一个微区室，是必不可少的碳浓缩机制（CCM），提高光合作用的真核藻类的性能。使用衣藻reinhardtii，我们获得了实验数据的光合作用，代谢产物和蛋白质在CCM诱导和CCM抑制的细胞。然后，我们采用了一种计算策略，以估计如何通过卡尔文-本森循环的流量划分之间的蛋白核和基质。我们的模型预测，核酮糖-1，5-二磷酸（RuBP），Rubisco的底物，和3-磷酸甘油酸（3 PGA），其产品，扩散的蛋白核，分别在CCM诱导的细胞中具有较高的通量。它还表明，有没有主要的扩散障碍，代谢通量之间的蛋白核和基质。我们的计算方法是理解其他生物体中微区室化CCM的垫脚石。
Cells and organelles are not homogeneous but include microcompartments that alter the spatiotemporal characteristics of cellular processes. The effects of microcompartmentation on metabolic pathways are however difficult to study experimentally. The pyrenoid is a microcompartment that is essential for a carbon concentrating mechanism (CCM) that improves the photosynthetic performance of eukaryotic algae. Using Chlamydomonas reinhardtii, we obtained experimental data on photosynthesis, metabolites, and proteins in CCM-induced and CCM-suppressed cells. We then employed a computational strategy to estimate how fluxes through the Calvin-Benson cycle are compartmented between the pyrenoid and the stroma. Our model predicts that ribulose-1,5-bisphosphate (RuBP), the substrate of Rubisco, and 3-phosphoglycerate (3PGA), its product, diffuse in and out of the pyrenoid, respectively, with higher fluxes in CCM-induced cells. It also indicates that there is no major diffusional barrier to metabolic flux between the pyrenoid and stroma. Our computational approach represents a stepping stone to understanding microcompartmentalized CCM in other organisms.