Dual targeting and function of a protease in mitochondria and chloroplasts
Dual targeting and function of a protease in mitochondria and chloroplasts
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DOI：
10.1038/sj.embor.7400011
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发表时间：
2003-11-01
期刊：
影响因子：
7.7
通讯作者：
Glaser, E
中科院分区：
文献类型：
--
作者：
Bhushan, S;Lefebvre, B;Glaser, E
在这里，我们表明，使用的绿色荧光蛋白（GFP）融合系统，拟南芥锌金属蛋白酶（AtZn-MP）的目标是线粒体和叶绿体。缺失突变体缺乏的氨基末端28个残基，翻译起始在第二个蛋氨酸残基，进口到叶绿体只。然而，全长靶向肽的突变形式，其中第二个甲硫氨酸残基被改变为亮氨酸，被输入到两个细胞器中。当在Zn-MP-GFP构建体的第一和第二ATG密码子之间引入移码突变时，没有检测到GFP荧光，表明没有替代的翻译起始。我们的研究结果表明，锌-MP的双重靶向是由于一个模糊的靶向肽。此外，我们表明，重组AtZn-MP降解线粒体和叶绿体靶向肽，表明其作为信号肽降解蛋白酶在线粒体和叶绿体的功能。
Here we show, using the green fluorescent protein (GFP) fusion system, that an Arabidopsis thaliana zinc-metalloprotease (AtZn-MP) is targeted to both mitochondria and chloroplasts. A deletion mutant lacking the amino-terminal 28 residues, with translation initiation at the second methionine residue, was imported into chloroplasts only. However, a mutated form of the full-length targeting peptide, in which the second methionine residue is changed to leucine, was imported to both organelles. No GFP fluorescence was detected when a frame-shift mutation was introduced between the first and second ATG codons of the Zn-MP-GFP construct, suggesting no alternative translational initiation. Our results show that the dual targeting of the Zn-MP is due to an ambiguous targeting peptide. Furthermore, we show that the recombinant AtZn-MP degrades mitochondrial and chloroplastic targeting peptides, indicating its function as a signal peptide degrading protease in both mitochondria and chloroplasts.