Insights on Structure and Function of a Late Embryogenesis Abundant Protein from Amaranthus cruentus: An Intrinsically Disordered Protein Involved in Protection against Desiccation, Oxidant Conditions, and Osmotic Stress.
Insights on Structure and Function of a Late Embryogenesis Abundant Protein from Amaranthus cruentus: An Intrinsically Disordered Protein Involved in Protection against Desiccation, Oxidant Conditions, and Osmotic Stress.
复制标题
DOI：
10.3389/fpls.2017.00497
复制
发表时间：
2017
影响因子：
5.6
通讯作者：
Barba de la Rosa AP
中科院分区：
文献类型：
--
作者：
Saucedo AL;Hernández-Domínguez EE;de Luna-Valdez LA;Guevara-García AA;Escobedo-Moratilla A;Bojorquéz-Velázquez E;Del Río-Portilla F;Fernández-Velasco DA;Barba de la Rosa AP
晚期胚胎发育丰富（莱亚）蛋白是一个大的蛋白质家族的一部分，保护其他蛋白质免于由于干燥或渗透胁迫而聚集。近年来，利用2D-PAGE对籽粒苋种子蛋白质组进行了研究，发现一个高积累的蛋白质点为莱亚蛋白，命名为Ac莱亚。将AcLEA cDNA克隆到表达载体中，并对重组蛋白进行纯化和鉴定。AcLEA编码172个氨基酸的多肽，预测分子量为18.34 kDa，估计pI为8.58。系统发育分析表明，AcLEA是进化接近LEA 3组。通过核磁共振和圆二色性方法揭示了其结构特征。我们已经表明，重组AcLEA是一个内在的无序蛋白质在溶液中，即使在高盐度和渗透压，但它有强烈的倾向，采取二级结构，主要折叠为α-螺旋，当诱导添加剂存在。重组AcLEA的功能进行了评价，大肠杆菌在体内模型显示出重要的保护作用，对干燥，氧化条件下，和渗透胁迫。AcLEA重组蛋白定位于本氏烟草原生质体细胞质中，并在野生和驯化阿马兰斯种子中检测到同源序列。有趣的是，在叶、茎和根中检测到AcLEA，但仅在遭受盐胁迫的植物中检测到。这一事实可能表明，在所有研究的阿马兰斯物种的植物胁迫过程中，AcLEA保护的重要作用。
Late embryogenesis abundant (LEA) proteins are part of a large protein family that protect other proteins from aggregation due to desiccation or osmotic stresses. Recently, the Amaranthus cruentus seed proteome was characterized by 2D-PAGE and one highly accumulated protein spot was identified as a LEA protein and was named AcLEA. In this work, AcLEA cDNA was cloned into an expression vector and the recombinant protein was purified and characterized. AcLEA encodes a 172 amino acid polypeptide with a predicted molecular mass of 18.34 kDa and estimated pI of 8.58. Phylogenetic analysis revealed that AcLEA is evolutionarily close to the LEA3 group. Structural characteristics were revealed by nuclear magnetic resonance and circular dichroism methods. We have shown that recombinant AcLEA is an intrinsically disordered protein in solution even at high salinity and osmotic pressures, but it has a strong tendency to take a secondary structure, mainly folded as α-helix, when an inductive additive is present. Recombinant AcLEA function was evaluated using Escherichia coli as in vivo model showing the important protection role against desiccation, oxidant conditions, and osmotic stress. AcLEA recombinant protein was localized in cytoplasm of Nicotiana benthamiana protoplasts and orthologs were detected in seeds of wild and domesticated amaranth species. Interestingly AcLEA was detected in leaves, stems, and roots but only in plants subjected to salt stress. This fact could indicate the important role of AcLEA protection during plant stress in all amaranth species studied.