Protein-protein interactions and metabolite channelling in the plant tricarboxylic acid cycle.
Protein-protein interactions and metabolite channelling in the plant tricarboxylic acid cycle.
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DOI：
10.1038/ncomms15212
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发表时间：
2017-05-16
影响因子：
16.6
通讯作者：
Obata T
中科院分区：
文献类型：
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作者：
Zhang Y;Beard KFM;Swart C;Bergmann S;Krahnert I;Nikoloski Z;Graf A;Ratcliffe RG;Sweetlove LJ;Fernie AR;Obata T
连续代谢酶的蛋白质复合物，通常称为代谢子，可以允许酶之间的代谢物直接通道，提供对代谢途径通量的增加的控制。支持它们在体内存在的实验证据仍然不完整。在本研究中，我们测试的二元相互作用的蛋白质构成的植物三羧酸（TCA）循环。我们整合了亲和纯化-质谱、分裂荧光素酶和酵母双杂交试验的（半）定量结果，以生成用于评估蛋白质-蛋白质相互作用的单一可靠性评分。通过这种方法，我们确定了158个相互作用，包括连续酶的催化亚基之间和介导非相邻反应的酶的亚基之间的相互作用。我们揭示了通道的柠檬酸盐和富马酸盐在分离的马铃薯线粒体同位素稀释实验。这些结果提供了一个功能性的TCA循环代谢在植物中，我们讨论的背景下，当代理解这一途径在其他王国的证据。代谢子是连续代谢酶的复合物，其在酶之间直接引导底物，从而优化代谢通量。Zhang等人提供了蛋白质相互作用和同位素稀释数据，支持在植物TCA循环中存在柠檬酸盐和富马酸盐通道的代谢子。
Protein complexes of sequential metabolic enzymes, often termed metabolons, may permit direct channelling of metabolites between the enzymes, providing increased control over metabolic pathway fluxes. Experimental evidence supporting their existence in vivo remains fragmentary. In the present study, we test binary interactions of the proteins constituting the plant tricarboxylic acid (TCA) cycle. We integrate (semi-)quantitative results from affinity purification-mass spectrometry, split-luciferase and yeast-two-hybrid assays to generate a single reliability score for assessing protein–protein interactions. By this approach, we identify 158 interactions including those between catalytic subunits of sequential enzymes and between subunits of enzymes mediating non-adjacent reactions. We reveal channelling of citrate and fumarate in isolated potato mitochondria by isotope dilution experiments. These results provide evidence for a functional TCA cycle metabolon in plants, which we discuss in the context of contemporary understanding of this pathway in other kingdoms. A metabolon is a complex of sequential metabolic enzymes that channels substrates directly between enzymes, thus optimizing metabolic flux. Here Zhang et al. provide protein interaction and isotope dilution data that support the existence of a metabolon that channels both citrate and fumarate in the plant TCA cycle.