The mammalian target of rapamycin (mTOR) pathway regulates mitochondrial oxygen consumption and oxidative capacity
The mammalian target of rapamycin (mTOR) pathway regulates mitochondrial oxygen consumption and oxidative capacity
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DOI：
10.1074/jbc.m603536200
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发表时间：
2006-09-15
影响因子：
4.8
通讯作者：
Finkel, Toren
中科院分区：
文献类型：
--
作者：
Schieke, Stefan M.;Phillips, Darci;Finkel, Toren
代谢率和随后产生的活性氧被认为有助于在广泛的物种老化的速度。雷帕霉素（TOR）的靶点是一种高度保守的丝氨酸/苏氨酸激酶，其响应于营养状态调节细胞生长。在这里，我们证明了在哺乳动物细胞中，哺乳动物TOR（mTOR）通路在决定静息耗氧量和氧化能力方面起着重要作用。特别是，我们证明了mTOR和它的一个已知的蛋白质伴侣raptor之间的复合物形成水平与整体线粒体活性相关。在用mTOR药理学抑制剂雷帕霉素处理后，这种复合物的破坏降低了线粒体膜电位、氧消耗和ATP合成能力。亚细胞分级显示，mTOR以及mTOR-raptor复合物可以在线粒体组分中纯化。使用二维差异凝胶电泳，我们进一步证明了雷帕霉素抑制mTOR导致线粒体磷酸化蛋白质组的显着改变。RNA干扰介导的TSC 2、p70 S6激酶（S6 K1）、raptor或rictor的敲低表明mTOR调节线粒体活性独立于其先前鉴定的细胞靶点。最后，我们证明，mTOR活性可能在确定线粒体和非线粒体来源的ATP生成之间的相对平衡中发挥重要作用。这些结果可以提供洞察最近的观察连接TOR通路的寿命调节较低的生物体。
Metabolic rate and the subsequent production of reactive oxygen species are thought to contribute to the rate of aging in a wide range of species. The target of rapamycin (TOR) is a well conserved serine/threonine kinase that regulates cell growth in response to nutrient status. Here we demonstrate that in mammalian cells the mammalian TOR (mTOR) pathway plays a significant role in determining both resting oxygen consumption and oxidative capacity. In particular, we demonstrate that the level of complex formation between mTOR and one of its known protein partners, raptor, correlated with overall mitochondrial activity. Disruption of this complex following treatment with the mTOR pharmacological inhibitor rapamycin lowered mitochondrial membrane potential, oxygen consumption, and ATP synthetic capacity. Subcellular fractionation revealed that mTOR as well as mTOR-raptor complexes can be purified in the mitochondrial fraction. Using two-dimensional difference gel electrophoresis, we further demonstrated that inhibiting mTOR with rapamycin resulted in a dramatic alteration in the mitochondrial phosphoproteome. RNA interference-mediated knockdown of TSC2, p70 S6 kinase (S6K1), raptor, or rictor demonstrates that mTOR regulates mitochondrial activity independently of its previously identified cellular targets. Finally we demonstrate that mTOR activity may play an important role in determining the relative balance between mitochondrial and non-mitochondrial sources of ATP generation. These results may provide insight into recent observations linking the TOR pathway to life span regulation of lower organisms.