Analysis of Copper-Binding Proteins in Rice Radicles Exposed to Excess Copper and Hydrogen Peroxide Stress.
Analysis of Copper-Binding Proteins in Rice Radicles Exposed to Excess Copper and Hydrogen Peroxide Stress.
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DOI：
10.3389/fpls.2016.01216
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发表时间：
2016
影响因子：
5.6
通讯作者：
Shen Z
中科院分区：
文献类型：
--
作者：
Zhang H;Xia Y;Chen C;Zhuang K;Song Y;Shen Z
铜是植物必需的微量营养元素，但过量的铜会在细胞水平上不可避免地与蛋白质结合，从而破坏蛋白质的功能。作为一种氧化还原活性金属，铜的毒性是由活性氧（ROS）的形成介导的。Cu结合结构基序可能通过降低细胞质中游离Cu ~（2+）的活性或清除ROS来减轻Cu诱导的损伤。鉴定与植物对Cu或ROS毒害反应有关的Cu结合蛋白，有助于我们进一步了解植物的金属毒害和耐性机制。采用固定化Cu 2+亲和层析、双向电泳和质谱分析技术，研究了过量Cu和氧化胁迫下萌发水稻种子胚根中Cu结合蛋白的变化。定量图像分析显示，26个蛋白质点显示了超过1.5倍的差异，在铜或H2 O2处理下的丰度与对照相比。这些铜结合蛋白与抗氧化防御、应激反应和解毒、蛋白质合成、蛋白质修饰和代谢调节等有关。结果表明，在24个已鉴定的铜结合蛋白中，有17个对低浓度铜有相似的反应在20 μM Cu和H_2O_2胁迫下，24株中有5株在低浓度和高浓度Cu胁迫下生长量增加（100 μM Cu），但在H2 O2强制降解下不受影响，提示Cu离子可通过H_2O_2或非H_2O_2途径调节Cu结合蛋白的积累，以科普细胞内过量的Cu。这些铜结合蛋白的变化规律及其功能分析为进一步研究铜离子在植物细胞铜结合蛋白中的作用提供了依据。
Copper (Cu) is an essential micronutrient for plants, but excess Cu can inactivate and disturb the protein function due to unavoidable binding to proteins at the cellular level. As a redox-active metal, Cu toxicity is mediated by the formation of reactive oxygen species (ROS). Cu-binding structural motifs may alleviate Cu-induced damage by decreasing free Cu2+ activity in cytoplasm or scavenging ROS. The identification of Cu-binding proteins involved in the response of plants to Cu or ROS toxicity may increase our understanding the mechanisms of metal toxicity and tolerance in plants. This study investigated change of Cu-binding proteins in radicles of germinating rice seeds under excess Cu and oxidative stress using immobilized Cu2+ affinity chromatography, two-dimensional electrophoresis, and mass spectra analysis. Quantitative image analysis revealed that 26 protein spots showed more than a 1.5-fold difference in abundances under Cu or H2O2 treatment compared to the control. The identified Cu-binding proteins were involved in anti-oxidative defense, stress response and detoxification, protein synthesis, protein modification, and metabolism regulation. The present results revealed that 17 out of 24 identified Cu-binding proteins have a similar response to low concentration Cu (20 μM Cu) and H2O2 stress, and 5 out of 24 were increased under low and high concentration Cu (100 μM Cu) but unaffected under H2O2 stress, which hint Cu ions can regulate Cu-binding proteins accumulation by H2O2 or no H2O2 pathway to cope with excess Cu in cell. The change pattern of these Cu-binding proteins and their function analysis warrant to further study the roles of Cu ions in these Cu-binding proteins of plant cells.