Consequences of impaired 1-MDa TIC complex assembly for the abundance and composition of chloroplast high-molecular mass protein complexes
Consequences of impaired 1-MDa TIC complex assembly for the abundance and composition of chloroplast high-molecular mass protein complexes
复制标题
1-MDa TIC 复合物组装受损对叶绿体高分子蛋白质复合物丰度和组成的影响
作者：
Peter Schäfer;Stefan Helm;D. Köhler;B. Agne;S. Baginsky
我们报道了利用天然凝胶电泳法和MSE绝对蛋白质定量相结合的方法对叶绿体高分子量蛋白质复合体的系统分析。利用这个实验装置，我们研究了1-丙二醛内膜转位酶(TIC)的tic56-3突变对叶绿体蛋白质组组装的影响。我们发现tic56-3突变导致1-丙二醛TIC复合体减少到野生型水平的大约10%。系统聚类证实了苹果酸脱氢酶(MDH)与包膜相关的FtsH/FtsHi复合体的关联，并暗示了富含甘氨酸的蛋白质与1-MDA TIC复合体的关联。这个复合体的耗尽导致叶绿体ATPase减少到大约。75%的野生型水平，而FtsH/FtsHi复合体的丰度增加到约140%的野生型。主要光合作用复合体的积累不受突变的影响，这表明TIC56-3植物尽管1-丙二醛TIC复合体显著减少，但仍能维持功能正常的光合作用机制。总之，我们的分析扩展了最近对叶绿体蛋白质天然分子质量进行分类的努力，并提供了关于叶绿体蛋白质组组装的1-丙二醛TIC转位酶受损积累的后果的信息。
We report a systematic analysis of chloroplast high-molecular mass protein complexes using a combination of native gel electrophoresis and absolute protein quantification by MSE. With this experimental setup, we characterized the effect of the tic56-3 mutation in the 1-MDa inner envelope translocase (TIC) on the assembly of the chloroplast proteome. We show that the tic56-3 mutation results in a reduction of the 1-MDa TIC complex to approximately 10% of wildtype levels. Hierarchical clustering confirmed the association of malate dehydrogenase (MDH) with an envelope-associated FtsH/FtsHi complex and suggested the association of a glycine-rich protein with the 1-MDa TIC complex. Depletion of this complex leads to a reduction of chloroplast ATPase to approx. 75% of wildtype levels, while the abundance of the FtsH/FtsHi complex is increased to approx. 140% of wildtype. The accumulation of the major photosynthetic complexes is not affected by the mutation, suggesting that tic56-3 plants can sustain a functional photosynthetic machinery despite a significant reduction of the 1-MDa TIC complex. Together our analysis expands recent efforts to catalogue the native molecular masses of chloroplast proteins and provides information on the consequences of impaired accumulation of the 1-MDa TIC translocase for chloroplast proteome assembly.
影响因子：
3.4
作者：
Schroeter, Yvonne;Steiner, Sebastian;Pfannschmidt, Thomas
通讯作者：
Pfannschmidt, Thomas