The Endoplasmic Reticulum Is the Main Membrane Source for Biogenesis of the Lytic Vacuole in Arabidopsis
The Endoplasmic Reticulum Is the Main Membrane Source for Biogenesis of the Lytic Vacuole in Arabidopsis
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DOI：
10.1105/tpc.113.114827
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发表时间：
2013-09-01
期刊：
影响因子：
11.6
通讯作者：
Schumacher, Karin
中科院分区：
文献类型：
--
作者：
Viotti, Corrado;Krueger, Falco;Schumacher, Karin
液泡是植物固着生活方式所必需的多功能细胞器。尽管它们在细胞生长、储存和解毒方面发挥着核心作用，但对它们的生物发生机制和相关的蛋白质运输途径的了解仍然有限。在这里，我们证明了在拟南芥根的分生细胞中，液泡的生物发生以及固醇和两种主要的液泡膜蛋白--液泡H+-焦磷酸酶和液泡H+-腺苷三磷酸酶的运输--独立于内质网(ER)-高尔基体运输和高尔基体后运输。相反，这两个泵都是在结构上类似自噬小体的前空泡中发现的，但不是由核心自噬机制形成的。综上所述，我们的结果表明，液泡的生物发生和液泡膜蛋白和脂类的运输可以直接从内质网发生，而不依赖高尔基体的功能。
Vacuoles are multifunctional organelles essential for the sessile lifestyle of plants. Despite their central functions in cell growth, storage, and detoxification, knowledge about mechanisms underlying their biogenesis and associated protein trafficking pathways remains limited. Here, we show that in meristematic cells of the Arabidopsis thaliana root, biogenesis of vacuoles as well as the trafficking of sterols and of two major tonoplast proteins, the vacuolar H+-pyrophosphatase and the vacuolar H+-adenosinetriphosphatase, occurs independently of endoplasmic reticulum (ER)-Golgi and post-Golgi trafficking. Instead, both pumps are found in provacuoles that structurally resemble autophagosomes but are not formed by the core autophagy machinery. Taken together, our results suggest that vacuole biogenesis and trafficking of tonoplast proteins and lipids can occur directly from the ER independent of Golgi function.