PEX11 proteins attract Mff and human Fis1 to coordinate peroxisomal fission
PEX11 proteins attract Mff and human Fis1 to coordinate peroxisomal fission
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DOI：
10.1242/jcs.102178
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发表时间：
2012-08-15
影响因子：
4
通讯作者：
Brocard, Cecile
中科院分区：
文献类型：
--
作者：
Koch, Johannes;Brocard, Cecile
膜结合细胞器的分裂需要膜重塑过程，以实现和促进分裂机器的组装。PEX 11家族的蛋白质在过氧化物酶体增殖过程中作为膜延伸因子发挥作用。此外，通过与裂变因子的相互作用，这些蛋白质协调膜断裂的进展。使用生物化学方法，我们确定了PEX 11 γ的膜拓扑结构，这是三种人类PEX 11蛋白之一。对定位于过氧化物酶体的PEX 11 γ突变体的分析揭示了膜延伸的必需结构域，包括两亲性区域及其调控序列。通过聚乙二醇化测定和体内研究，我们确定PEX 11 γ序列包括两个膜锚定结构域，其将两亲性区域对接到过氧化物酶体膜上，从而调节其延伸。野生型和突变型PEX 11 γ的相互作用曲线揭示了同源和异源二聚化之间的重排以及与裂变因子的关联。我们还证明了存在的线粒体裂变因子Mff的过氧化物酶体及其与PEX 11蛋白的相互作用。我们的数据揭示了哺乳动物细胞中过氧化物酶体增殖的分子机制的几个特征：（1）PEX 11 γ是必需的，并且与至少一种其他PEX 11蛋白协同作用以突出过氧化物酶体膜;（2）PEX 11蛋白将Mff和人Fis 1（hFis 1）吸引到它们的作用位点;（3）PEX 11蛋白的协同作用为过氧化物酶体的生长和分裂提供了时空控制。
Fission of membrane-bound organelles requires membrane remodeling processes to enable and facilitate the assembly of the scission machinery. Proteins of the PEX11 family were shown to act as membrane elongation factors during peroxisome proliferation. Furthermore, through interaction with fission factors these proteins coordinate progression of membrane scission. Using a biochemical approach, we determined the membrane topology of PEX11 gamma, one of the three human PEX11 proteins. Analysis of PEX11 gamma mutants, which localize to peroxisomes, revealed essential domains for membrane elongation including an amphipathic region and regulatory sequences thereof. Through pegylation assays and in vivo studies, we establish that the PEX11 gamma sequence includes two membrane-anchored domains, which dock an amphipathic region onto the peroxisomal membrane thereby regulating its elongation. The interaction profile of wild-type and mutant PEX11 gamma and reveals a rearrangement between homo-and heterodimerization and association with fission factors. We also demonstrate the presence of the mitochondrial fission factor Mff on peroxisomes and its interaction with PEX11 proteins. Our data reveal several features of the molecular mechanism of peroxisome proliferation in mammalian cells: (1) PEX11 gamma is required and acts in coordination with at least one of the other PEX11 proteins to protrude the peroxisomal membrane; (2) PEX11 proteins attract both Mff and human Fis1 (hFis1) to their site of action; and (3) the concerted interaction of PEX11 proteins provides spatiotemporal control for growth and division of peroxisomes.