Pyrenoid functions revealed by proteomics in Chlamydomonas reinhardtii
Pyrenoid functions revealed by proteomics in Chlamydomonas reinhardtii
复制标题
蛋白质组学揭示莱茵衣藻的核苷功能
作者：
Yu Zhan;C. Marchand;Alexandre Maes;Adeline Mauriès;Yi Sun;James S. Dhaliwal;J. Uniacke;Simon Arragain;Heng Jiang;Nicholas D. Gold;V. Martin;S. Lemaire;W. Zerges
细胞器是细胞内的区室，它们本身是分隔的。生物和代谢过程被定位到专门的域或微区室，以提高其效率并抑制有害的副反应。细胞器内区室化的一个例子是藻类和金鱼藻叶绿体中的蛋白核。该微室增强了卡尔文-本森循环酶Rubisco的光合CO2固定活性，抑制了Rubisco的能量浪费加氧酶活性，并减轻了水生环境中CO2可用性的限制。因此，蛋白核在功能上类似于蓝藻中的羧基体。然而，缺乏基于其蛋白质组成的蛋白核功能的全面分析。在这里，我们报告的蛋白质组学特性的蛋白核蛋白在绿色衣藻莱茵衣藻。通过定量质谱法分析类核蛋白富集级分。通过蛋白核缺陷突变体的平行分析鉴定污染蛋白。这种蛋白质组包含190种蛋白质，其中许多蛋白质在已知或建议在蛋白质中发生的过程中起作用：例如碳浓缩机制，淀粉代谢或RNA代谢和翻译。利用放射性同位素脉冲标记实验，我们表明，蛋白核相关的核糖体可以从事大亚基的Rubisco的本地化合成。新的类蛋白核功能由四吡咯和叶绿素合成、类胡萝卜素代谢或氨基酸代谢中的蛋白质支持。因此，我们的研究结果支持了长期存在的假设，即蛋白核是代谢的枢纽。这81种功能未知的蛋白质揭示了这些过程中新参与者的候选者。我们的研究结果提供了蛋白核功能的生化证据，并为今后研究蛋白核及其用于提高农业植物生产力提供了资源。数据可通过ProteomeXchange获得，标识符为PXD 004509。
Organelles are intracellular compartments which are themselves compartmentalized. Biogenic and metabolic processes are localized to specialized domains or microcompartments to enhance their efficiency and suppress deleterious side reactions. An example of intra-organellar compartmentalization is the pyrenoid in the chloroplasts of algae and hornworts. This microcompartment enhances the photosynthetic CO2-fixing activity of the Calvin-Benson cycle enzyme Rubisco, suppresses an energetically wasteful oxygenase activity of Rubisco, and mitigates limiting CO2 availability in aquatic environments. Hence, the pyrenoid is functionally analogous to the carboxysomes in cyanobacteria. However, a comprehensive analysis of pyrenoid functions based on its protein composition is lacking. Here we report a proteomic characterization of the pyrenoid in the green alga Chlamydomonas reinhardtii. Pyrenoid-enriched fractions were analyzed by quantitative mass spectrometry. Contaminant proteins were identified by parallel analyses of pyrenoid-deficient mutants. This pyrenoid proteome contains 190 proteins, many of which function in processes that are known or proposed to occur in pyrenoids: e.g. the carbon concentrating mechanism, starch metabolism or RNA metabolism and translation. Using radioisotope pulse labeling experiments, we show that pyrenoid-associated ribosomes could be engaged in the localized synthesis of the large subunit of Rubisco. New pyrenoid functions are supported by proteins in tetrapyrrole and chlorophyll synthesis, carotenoid metabolism or amino acid metabolism. Hence, our results support the long-standing hypothesis that the pyrenoid is a hub for metabolism. The 81 proteins of unknown function reveal candidates for new participants in these processes. Our results provide biochemical evidence of pyrenoid functions and a resource for future research on pyrenoids and their use to enhance agricultural plant productivity. Data are available via ProteomeXchange with identifier PXD004509.
DOI：
10.1016/j.bbrc.2008.05.058
发表时间：
2008-07
影响因子：
3.1
作者：
Jinhua Wu;Zhongwei Li
通讯作者：
Jinhua Wu;Zhongwei Li
DOI：
10.1073/pnas.1522866113
发表时间：
2016-05-24
影响因子：
11.1
作者：
Mackinder, Luke C. M.;Meyer, Moritz T.;Jonikas, Martin C.
通讯作者：
Jonikas, Martin C.
影响因子：
2.9
作者：
Wu, Jinhua;Jiang, Zhe;Liu, Min;Gong, Xin;Wu, Shaohui;Burns, Christopher M.;Li, Zhongwei
通讯作者：
Li, Zhongwei