Multiple kinesin-14 family members drive microtubule minus end-directed transport in plant cells.
Multiple kinesin-14 family members drive microtubule minus end-directed transport in plant cells.
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DOI：
10.1083/jcb.201610065
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发表时间：
2017-06-05
期刊：
影响因子：
--
通讯作者：
Goshima G
中科院分区：
文献类型：
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作者：
Yamada M;Tanaka-Takiguchi Y;Hayashi M;Nishina M;Goshima G
在植物细胞中，细胞核和叶绿体等细胞内物质沿着沿着微管向负端转运，尽管植物已经失去了编码细胞质动力蛋白的基因，细胞质动力蛋白是动物中主要的负端定向转运蛋白。Yamada等人鉴定了多个驱动蛋白-14运动家族成员作为苔藓细胞中的负末端定向转运蛋白。在多种细胞类型中，微管（MT）沿着负末端定向货物运输完全由分子马达动力蛋白驱动。有趣的是，在进化过程中，植物失去了编码动力蛋白的基因;补偿动力蛋白功能的MT马达是未知的。在这里，我们表明，两个成员的驱动蛋白-14家庭驱动器减去在植物中的末端定向运输。苔藓小立碗藓的基因敲除分析表明，植物特异性的VI类驱动蛋白-14，KCBP，是核和叶绿体的负末端定向运输所必需的。纯化的KCBP在体外可直接与酸性磷脂结合，并可沿沿着MT单向转运磷脂脂质体。因此，负端定向运输的膜货物可能是由他们的直接相互作用与这个马达蛋白。新的有核细胞质MT代表另一种已知的货物表现出负末端定向运动，我们确定了保守的I类驱动蛋白-14（ATK）作为参与的马达。这些结果表明，驱动蛋白-14马达复制和开发的替代MT为基础的减去最终定向运输在陆地植物。
Intracellular cargoes such as the nucleus and chloroplast are transported along microtubules toward minus ends in plant cells, despite the fact that plants have lost the genes encoding cytoplasmic dynein, a major minus end–directed transporter in animals. Yamada et al. identify multiple kinesin-14 motor family members as the minus end–directed transporters in moss cells. Minus end–directed cargo transport along microtubules (MTs) is exclusively driven by the molecular motor dynein in a wide variety of cell types. Interestingly, during evolution, plants have lost the genes encoding dynein; the MT motors that compensate for dynein function are unknown. Here, we show that two members of the kinesin-14 family drive minus end–directed transport in plants. Gene knockout analyses of the moss Physcomitrella patens revealed that the plant-specific class VI kinesin-14, KCBP, is required for minus end–directed transport of the nucleus and chloroplasts. Purified KCBP directly bound to acidic phospholipids and unidirectionally transported phospholipid liposomes along MTs in vitro. Thus, minus end–directed transport of membranous cargoes might be driven by their direct interaction with this motor protein. Newly nucleated cytoplasmic MTs represent another known cargo exhibiting minus end–directed motility, and we identified the conserved class I kinesin-14 (ATK) as the motor involved. These results suggest that kinesin-14 motors were duplicated and developed as alternative MT-based minus end–directed transporters in land plants.