Viotti Corrado, Krüger Falco, Krebs Melanie, Neubert Christoph, Fink Fabian, Lupanga Upendo, Scheuring David, Boutté Yohann, Frescatada-Rosa Márcia, Wolfenstetter Susanne, Sauer Norbert, Hillmer Stefan, Grebe Markus, Schumacher Karin
Centre for Organismal Studies, Plant Developmental Biology, University of Heidelberg, 69120 Heidelberg, Germany.
Plant Cell. 2013 Sep;25(9):3434-49. doi: 10.1105/tpc.113.114827. Epub 2013 Sep 6.
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.
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、储存和解毒中发挥着核心作用，但关于其生物发生机制及相关蛋白质运输途径的知识仍然有限。在这里，我们表明，在拟南芥根的分生组织细胞中，液泡的生物发生以及固醇和两种主要液泡膜蛋白（液泡H(+) - 焦磷酸酶和液泡H(+) - 三磷酸腺苷酶）的运输独立于内质网（ER）-高尔基体和高尔基体后运输发生。相反，这两种泵存在于前液泡中，前液泡在结构上类似于自噬体，但不是由核心自噬机制形成的。综上所述，我们的结果表明，液泡生物发生以及液泡膜蛋白和脂质的运输可以直接从内质网发生，而不依赖于高尔基体功能。
