Probing the membrane environment of the TOR kinases reveals functional interactions between TORC1, actin, and membrane trafficking in Saccharomyces cerevisiae
Probing the membrane environment of the TOR kinases reveals functional interactions between TORC1, actin, and membrane trafficking in Saccharomyces cerevisiae
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DOI：
10.1091/mbc.e07-03-0274
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发表时间：
2007-08-01
影响因子：
3.3
通讯作者：
Powers, Ted
中科院分区：
文献类型：
--
作者：
Aronova, Sofia;Wedaman, Karen;Powers, Ted
TOR激酶是真核细胞中生长的调节剂，组装成两种不同的蛋白质复合物，TORC 1和TORC 2，其中TORC 1被抗生素雷帕霉素抑制。目前的模型有利于一个观点，其中TORC 1调节细胞质量的积累，TORC 2调节空间方面的增长，包括肌动蛋白细胞骨架的组织。在这里，我们证明了在酵母中，TORC 1和TORC 2都具有一种新形式的耐洗涤剂膜，这种膜不同于耐洗涤剂质膜“筏”。“这些TOR相关膜的蛋白质组学分析揭示了内吞作用和肌动蛋白细胞骨架调节因子的存在。遗传分析揭示了这些组件和TORC 1之间的相互作用的显着数量，证明了TORC 1和肌动蛋白/内吞相关基因之间的功能联系。此外，我们发现，雷帕霉素抑制TORC 1 1）破坏肌动蛋白极化，2）延迟葡萄糖饥饿后肌动蛋白复极化，3）延迟荧光黄在液泡内的积累。通过将我们的遗传结果与数据库挖掘相结合，我们构建了一个相互作用图，从而确定了TORC 1与膜运输相关组件之间的其他遗传相互作用。总之，这些结果揭示了受TORC 1影响的细胞过程的广泛范围，并且它们强调了TORC 1和TORC 2之间的功能重叠。
The TOR kinases are regulators of growth in eukaryotic cells that assemble into two distinct protein complexes, TORC1 and TORC2, where TORC1 is inhibited by the antibiotic rapamycin. Present models favor a view wherein TORC1 regulates cell mass accumulation, and TORC2 regulates spatial aspects of growth, including organization of the actin cytoskeleton. Here, we demonstrate that in yeast both TORC1 and TORC2 fractionate with a novel form of detergent-resistant membranes that are distinct from detergent-resistant plasma membrane "rafts." Proteomic analysis of these TOR-associated membranes revealed the presence of regulators of endocytosis and the actin cytoskeleton. Genetic analyses revealed a significant number of interactions between these components and TORC1, demonstrating a functional link between TORC1 and actin/endocytosis-related genes. Moreover, we found that inhibition of TORC1 by rapamycin 1) disrupted actin polarization, 2) delayed actin repolarization after glucose starvation, and 3) delayed accumulation of lucifer yellow within the vacuole. By combining our genetic results with database mining, we constructed a map of interactions that led to the identification of additional genetic interactions between TORC1 and components involved in membrane trafficking. Together, these results reveal the broad scope of cellular processes influenced by TORC1, and they underscore the functional overlap between TORC1 and TORC2.