Peroxisomes, lipid droplets, and endoplasmic reticulum "hitchhike" on motile early endosomes.
Peroxisomes, lipid droplets, and endoplasmic reticulum "hitchhike" on motile early endosomes.
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DOI：
10.1083/jcb.201505086
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发表时间：
2015-12-07
期刊：
影响因子：
--
通讯作者：
Steinberg G
中科院分区：
文献类型：
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作者：
Guimaraes SC;Schuster M;Bielska E;Dagdas G;Kilaru S;Meadows BR;Schrader M;Steinberg G
早期内体的微管依赖性长程运动支持过氧化物酶体、脂滴和内质网的定向运动，并且该过程由所有三种细胞器和内体之间的瞬时相互作用介导。细胞内转运是由分子马达介导的，分子马达结合货物以沿着细胞骨架沿着转运。在这里，我们报告，为第一次，过氧化物酶体（PO），脂滴（LD），和内质网（ER）依赖于早期内涵体（EE）在真菌模型系统的细胞内运动。我们发现，PO进行驱动蛋白-3-和动力蛋白依赖运输沿着微管。令人惊讶的是，驱动蛋白-3不与PO共定位。相反，电机移动EE，EE拖动PO通过单元。当EE运动在各种突变体中被阻断时，PO运动被废除。大多数LD和ER运动也依赖于EE运动，而线粒体运动独立于EE。共可视化研究表明，EE介导的ER运动不需要PO或LD运动，这表明细胞器与EE相互作用独立。在EE运动的情况下，PO和LDs集群在生长的尖端，而ER是部分收缩到根尖下区域。总的来说，我们的研究结果表明，移动EE与其他细胞器瞬时相互作用，从而介导其定向运输和分布在细胞中。
Microtubule-dependent long-range motility of early endosomes supports directed motility of peroxisomes, lipid droplets, and endoplasmic reticulum, and this process is mediated by transient interaction between all three organelles and the endosomes. Intracellular transport is mediated by molecular motors that bind cargo to be transported along the cytoskeleton. Here, we report, for the first time, that peroxisomes (POs), lipid droplets (LDs), and the endoplasmic reticulum (ER) rely on early endosomes (EEs) for intracellular movement in a fungal model system. We show that POs undergo kinesin-3– and dynein-dependent transport along microtubules. Surprisingly, kinesin-3 does not colocalize with POs. Instead, the motor moves EEs that drag the POs through the cell. PO motility is abolished when EE motility is blocked in various mutants. Most LD and ER motility also depends on EE motility, whereas mitochondria move independently of EEs. Covisualization studies show that EE-mediated ER motility is not required for PO or LD movement, suggesting that the organelles interact with EEs independently. In the absence of EE motility, POs and LDs cluster at the growing tip, whereas ER is partially retracted to subapical regions. Collectively, our results show that moving EEs interact transiently with other organelles, thereby mediating their directed transport and distribution in the cell.