The Arabidopsis Tail-Anchored Protein PEROXISOMAL AND MITOCHONDRIAL DIVISION FACTOR1 Is Involved in the Morphogenesis and Proliferation of Peroxisomes and Mitochondria
The Arabidopsis Tail-Anchored Protein PEROXISOMAL AND MITOCHONDRIAL DIVISION FACTOR1 Is Involved in the Morphogenesis and Proliferation of Peroxisomes and Mitochondria
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DOI：
10.1105/tpc.111.090142
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发表时间：
2011-12-01
期刊：
影响因子：
11.6
通讯作者：
Hu, Jianping
中科院分区：
文献类型：
--
作者：
Aung, Kyaw;Hu, Jianping
过氧化物酶体和线粒体是多功能的真核细胞器，它们不仅在代谢上相互联系，而且在分裂时共享蛋白质。两个进化上保守的分裂因子——动力蛋白相关蛋白（DRP）及其细胞器锚定蛋白FIS1 （FIS1）介导过氧化物酶体和线粒体的裂变。在这里，我们鉴定并表征了这两种细胞器共享的植物特异性蛋白。拟南芥过氧化物酶体和线粒体分裂因子1 （PMD1）是一种螺旋状蛋白，通过其C端连接在过氧化物酶体和线粒体的膜上。PMD1的零突变体含有增大的过氧化物酶体和延长的线粒体，过表达PMD1的植物有更多的这些细胞器，它们的大小更小，经常聚集。PMD1与已知的分裂蛋白DRP3和FIS1缺乏物理相互作用；DRP3的细胞器靶向也不需要它。亲和纯化去除PMD1的同源物PMD2， PMD2专门针对线粒体并在线粒体形态发生中起特定作用。PMD1和PMD2可以形成同质复合物和异质复合物。细胞器靶向信号驻留在这些蛋白的C端。我们的研究结果表明，PMD1以不依赖于FIS1/ drp3的方式促进过氧化物酶体和线粒体的增殖，同源蛋白PMD1和PMD2在细胞器形态发生中发挥非冗余功能。
Peroxisomes and mitochondria are multifunctional eukaryotic organelles that are not only interconnected metabolically but also share proteins in division. Two evolutionarily conserved division factors, dynamin-related protein (DRP) and its organelle anchor FISSION1 (FIS1), mediate the fission of both peroxisomes and mitochondria. Here, we identified and characterized a plant-specific protein shared by these two types of organelles. The Arabidopsis thaliana PEROXISOMAL and MITOCHONDRIAL DIVISION FACTOR1 (PMD1) is a coiled-coil protein tethered to the membranes of peroxisomes and mitochondria by its C terminus. Null mutants of PMD1 contain enlarged peroxisomes and elongated mitochondria, and plants overexpressing PMD1 have an increased number of these organelles that are smaller in size and often aggregated. PMD1 lacks physical interaction with the known division proteins DRP3 and FIS1; it is also not required for DRP3's organelle targeting. Affinity purifications pulled down PMD1's homolog, PMD2, which exclusively targets to mitochondria and plays a specific role in mitochondrial morphogenesis. PMD1 and PMD2 can form homo- and heterocomplexes. Organelle targeting signals reside in the C termini of these proteins. Our results suggest that PMD1 facilitates peroxisomal and mitochondrial proliferation in a FIS1/DRP3-independent manner and that the homologous proteins PMD1 and PMD2 perform nonredundant functions in organelle morphogenesis.