Peroxisomes move by hitchhiking on early endosomes using the novel linker protein PxdA
Peroxisomes move by hitchhiking on early endosomes using the novel linker protein PxdA
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DOI：
10.1101/034231
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发表时间：
2015-12
期刊：
影响因子：
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通讯作者：
J. Salogiannis;M. Egan;Samara L. Reck-Peterson
中科院分区：
文献类型：
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作者：
J. Salogiannis;M. Egan;Samara L. Reck-Peterson
真核细胞使用基于微管的细胞内转运来递送许多亚细胞货物，包括细胞器。细胞器运输的经典观点是细胞器通过货物特异性衔接子直接招募分子马达。与此相反，我们在这里表明，过氧化物酶体移动搭便车的早期内涵体，直接招募运输机械的细胞器。使用丝状真菌构巢曲霉，我们发现搭便车是由一种新的内体相关的连接蛋白，PxdA。PxdA是过氧化物酶体的正常分布和长程运动所必需的，但不是早期内体或细胞核。使用同步延时成像，我们发现，早期内体相关PxdA定位到移动过氧化物酶体的前沿。我们确定了一个卷曲螺旋区域内PxdA是必要的和足够的早期内体定位和过氧化物酶体的分布和运动。这些结果提出了一种基于微管的细胞器转运的新机制，其中过氧化物酶体在早期核内体上搭便车，并确定PxdA是这种偶联所需的新型接头蛋白。
Eukaryotic cells use microtubule-based intracellular transport for the delivery of many subcellular cargos, including organelles. The canonical view of organelle transport is that organelles directly recruit molecular motors via cargo-specific adaptors. In contrast to this view, we show here that peroxisomes move by hitchhiking on early endosomes, an organelle that directly recruits the transport machinery. Using the filamentous fungus Aspergillus nidulans we find that hitchhiking is mediated by a novel endosome-associated linker protein, PxdA. PxdA is required for normal distribution and long-range movement of peroxisomes, but not early endosomes or nuclei. Using simultaneous time-lapse imaging we find that early endosome-associated PxdA localizes to the leading edge of moving peroxisomes. We identify a coiled-coil region within PxdA that is necessary and sufficient for early endosome localization and peroxisome distribution and motility. These results present a new mechanism of microtubule-based organelle transport where peroxisomes hitchhike on early endosomes and identify PxdA as the novel linker protein required for this coupling.