mTOR通过YY1-PGC-1alpha转录复合体控制线粒体的氧化功能.
John T Cunningham1, Joseph T Rodgers, Daniel H Arlow
1Dana-Farber Cancer Institute and Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|November 30, 2007
概括
猛素 (mTOR) 的哺乳动物点对线粒体的氧化功能至关重要. mTOR通过转录因子YY1调节线粒体基因表达和氧气消耗,影响能量恒温.
科学领域:
- 细胞的新陈代谢
- 线粒体生物学 线粒体生物学
- 分子内分泌学分子内分泌学
背景情况:
- Peroxisome-proliferator-activated receptor coactivator (PGC)-1alpha调节了线粒体的氧化功能和能量恒温. 这一作用是为了促进细胞的能量稳定.
- 猛素的哺乳动物点 (mTOR) 是营养和能量通路中的关键激酶,控制细胞生长和存活.
- mTOR在调节线粒体氧化活性中的确切作用尚不清楚.
研究的目的:
- 调查mTOR是否以及如何控制线粒体的氧化活动.
- 阐明将mTOR信号与线粒体功能联系起来的分子机制.
- 确定代谢疾病和癌症的潜在治疗点.
主要方法:
- 在骨肌肉组织和细胞中利用拉巴胺抑制mTOR.
- 评估了线粒体转录调节者的基因表达 (PGC-1alpha,雌激素相关受体α,核呼吸因子).
- 采用计算基因组学来识别转录因子标,随后进行基因淘汰研究和蛋白质-蛋白质相互作用测试.
主要成果:
- mTOR抑制降低了PGC-1α,雌激素相关受体α和核呼吸因子的表达,减少了线粒体基因表达和氧气消耗.
- 确定了阴阳1 (YY1) 作为mTOR和PGC-1alpha的共同转录标.
- YY1倒置显著降低了线粒体基因表达和呼吸;YY1是mTOR抑制诱导的基因抑制所需的. mTOR和猛禽与YY1相互作用,mTOR的抑制破坏了YY1-PGC-1alpha相互作用和协同激活.
结论:
- mTOR对于维护线粒体的氧化功能至关重要.
- 一个新的机制揭示了mTOR信号通过对YY1和PGC-1alpha的转录控制来调节线粒体的氧化功能.
- 这一途径对平衡能量代谢至关重要,对代谢疾病和癌症有影响.
相关概念视频
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
Mitochondrial Precursor Proteins
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial precursors...
Most of the mitochondrial precursors...
Mitochondria
Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
Mitochondria
Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
Mitochondrial Membranes
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...


