Dubinin Juri, Braun Hans-Peter, Schmitz Udo, Colditz Frank
Leibniz University of Hannover, Institute for Plant Genetics, Hannover, Germany.
Biochim Biophys Acta. 2011 Dec;1814(12):1658-68. doi: 10.1016/j.bbapap.2011.08.008. Epub 2011 Aug 22.
Legumes carry out special biochemical functions, e.g. the fixation of molecular nitrogen based on a symbiosis with proteobacteria. At the cellular level, this symbiosis has to be implemented into the energy metabolism of the host cell. To provide a basis for future analyses, we have characterized the protein complement of mitochondria of the model legume Medicago truncatula using two-dimensional isoelectric focussing (IEF) and blue-native (BN)-SDS-PAGE. While the IEF reference map resulted mainly in resolution of those proteins associated with the mitochondrial matrix, the BN proteomic map allowed separation of protein subunits from the respiratory chain protein complexes, which are located in the organelle's inner membrane. The M. truncatula mitochondrial BN reference map revealed some striking similarities to the one from Arabidopsis thaliana but at the same time exhibited also some special features: complex II is of increased abundance and additionally represented by a low molecular mass form not reported for Arabidopsis. Furthermore three highly abundant forms of prohibitin complexes are present in the mitochondrial proteome of M. truncatula. Special features with respect to mitochondrial protein complexes might reflect adaptations of legumes to elevated cellular energy requirements enabling them to develop symbiotic interactions with rhizobial bacteria.
豆科植物具有特殊的生化功能，例如基于与变形菌的共生作用进行分子氮的固定。在细胞水平上，这种共生关系必须融入宿主细胞的能量代谢中。为了为未来的分析提供基础，我们使用二维等电聚焦（IEF）和蓝色天然（BN）-SDS-PAGE对模式豆科植物蒺藜苜蓿线粒体的蛋白质组进行了表征。虽然IEF参考图谱主要解析了与线粒体基质相关的蛋白质，但BN蛋白质组图谱允许分离位于细胞器内膜的呼吸链蛋白复合物的蛋白质亚基。蒺藜苜蓿线粒体BN参考图谱与拟南芥的图谱有一些显著的相似之处，但同时也表现出一些特殊特征：复合物II丰度增加，并且还存在一种拟南芥未报道的低分子量形式。此外，蒺藜苜蓿的线粒体蛋白质组中存在三种高度丰富的 prohibitin 复合物形式。线粒体蛋白复合物的特殊特征可能反映了豆科植物对细胞能量需求增加的适应性，使它们能够与根瘤菌发展共生相互作用。
