A membrane trafficking pathway regulated by the plant-specific RAB GTPase ARA6
A membrane trafficking pathway regulated by the plant-specific RAB GTPase ARA6
复制标题
DOI：
10.1038/ncb2270
复制
发表时间：
2011-07-01
影响因子：
21.3
通讯作者：
Ueda, Takashi
中科院分区：
文献类型：
--
作者：
Ebine, Kazuo;Fujimoto, Masaru;Ueda, Takashi
内体运输在各种真核细胞活动中发挥着不可或缺的作用，并且是多细胞生物中高级功能的基础。对植物内体运输重要性的理解正在迅速发展（1，2），但其分子机制大多是未知的。内体运输的几个关键调节因子，包括调节动物细胞中多种内吞事件的RAB 5（3，4），是高度保守的。然而，真核生物中谱系特异性调节因子的鉴定表明，内体运输根据不同的身体计划和生活方式而多样化。除了后生动物RAB 5的直向同源物之外，陆生植物还具有独特的RAB 5分子，这是植物RAB GT酶组织的最显著特征之一（5，6）。植物还进化出了独特的SNARE库，其中最具特色的是多种与VAMP7相关的长链蛋白，包括植物特有的VAMP72衍生物（7）。在这里，我们证明了植物独特的RAB 5蛋白，ARA 6，在拟南芥的内体运输途径的行为。ARA6调节与传统RAB 5不同的SNARE复合物的组装，并且在盐度胁迫响应中具有功能性作用。我们的研究结果表明，植物具有独特的内体运输网络，并提供了第一个指示的功能之间的联系，一个特定的RAB和一个特定的陷阱复杂的植物。
Endosomal trafficking plays an integral role in various eukaryotic cell activities and serves as a basis for higher-order functions in multicellular organisms. An understanding of the importance of endosomal trafficking in plants is rapidly developing(1,2), but its molecular mechanism is mostly unknown. Several key regulators of endosomal trafficking, including RAB5, which regulates diverse endocytic events in animal cells(3,4), are highly conserved. However, the identification of lineage-specific regulators in eukaryotes indicates that endosomal trafficking is diversified according to distinct body plans and life styles. In addition to orthologues of metazoan RAB5, landplants possess a unique RAB5 molecule, which is one of the most prominent features of plant RAB GTPase organization(5,6). Plants have also evolved a unique repertoire of SNAREs, the most distinctive of which are diverse VAMP7-related longins, including plant-unique VAMP72 derivatives(7). Here, we demonstrate that a plant-unique RAB5 protein, ARA6, acts in an endosomal trafficking pathway in Arabidopsis thaliana. ARA6 modulates the assembly of a distinct SNARE complex from conventional RAB5, and has a functional role in the salinity stress response. Our results indicate that plants possess a unique endosomal trafficking network and provide the first indication of a functional link between a specific RAB and a specific SNARE complex in plants.