Protein Aggregates are Transported to Vacuoles by Macroautophagic Mechanism in Nutrient-Starved Plant Cells
Protein Aggregates are Transported to Vacuoles by Macroautophagic Mechanism in Nutrient-Starved Plant Cells
复制标题
DOI：
10.4161/auto.2.2.2366
复制
发表时间：
2006-01
期刊：
影响因子：
13.3
通讯作者：
K. Toyooka;Y. Moriyasu;Yumi Goto;Masaki Takeuchi;H. Fukuda;K. Matsuoka
中科院分区：
文献类型：
--
作者：
K. Toyooka;Y. Moriyasu;Yumi Goto;Masaki Takeuchi;H. Fukuda;K. Matsuoka
当细胞色素b5（Cyt b5）和红色荧光蛋白（RFP）的融合蛋白在烟草BY-2细胞中表达时，所表达的蛋白形成发射红色荧光的细胞内聚集体。当这些细胞生长到稳定期或与营养限制培养基一起孵育时，可以在液泡腔中检测到RFP荧光。我们研究了这种运输机制，使用有限的氮模型。抑制自噬过程的E-64和3-甲基腺嘌呤抑制RFP信号向液泡的运输。接下来，我们使用与烟草Atg 8同源物融合的YFP（YFP-NtAtg 8）追踪烟草细胞中的自噬过程，并分析自噬对聚集体的液泡运输的贡献。在有限的氮条件下，聚集体优先于其他细胞器被降解，并且自噬体与聚集体共定位的频率高于线粒体。这是第一次证明，选择性macroautophagic降解发生在植物细胞。
When a fusion protein of cytochrome b5 (Cyt b5) and the red fluorescent protein (RFP) are expressed in tobacco BY-2 cells, the expressed protein forms intracellular aggregates that emit red fluorescence. When such cells are grown to the stationary phase or incubated with nutrient limit medium, RFP fluorescence can be detected in the vacuolar lumen. We investigated this transport mechanism using a limited-nitrogen model. E-64 and 3-methyladenine, which inhibit authophagic processes, inhibited the transport of RFP signal to the vacuole. We next traced the autophagic process in tobacco cells using YFP fused with the tobacco Atg8 homologue (YFP–NtAtg8) and analyzed the contribution of autophagy to the vacuolar transport of the aggregates. Under limited-nitrogen conditions, the aggregates were degraded in preference to otherorganelles, and the autophagosomes colocalized with the aggregates at a higher frequency than with mitochondria. This is the first demonstration that selective macroautophagic degradation occurs in plant cells.