mTORC1通过GCN2感知谷氨酸和其他氨基酸
Gianluca Figlia1,2,3,4, Sandra Müller5,6,7, Fabiola Garcia-Cortizo5,6,7
1Signal Transduction in Cancer and Metabolism, German Cancer Research Center (DKFZ), Heidelberg, 69120, Germany. gfiglia@ukaachen.de.
The EMBO journal
|July 21, 2025
概括
蛋白质激酶GCN2感知着mTORC1的谷氨酸可用性,不是直接,而是通过阿斯巴拉金减少. 这种GCN2通路,以及专门的传感器,使mTORC1能够监测细胞生长调节的各种氨基酸.
科学领域:
- 细胞生物学 细胞生物学
- 营养物质感应的分子机制
- 蛋白质激酶信号传递
背景情况:
- mTORC1 (拉巴胺素复合体1的机械标) 是细胞生长的中央调节器,由营养物质,特别是氨基酸的可用性激活.
- 虽然已知氨酸,氨酸和氨酸的传感器,但mTORC1感知谷氨酸的机制仍然难以捉摸.
- 谷氨胺是一种强大的mTORC1诱导剂,突出了理解营养介导生长控制的差距.
研究的目的:
- 阐明mTORC1感知谷氨酸可用性的机制.
- 确定参与谷氨酸中介的mTORC1抑制的上游调节器和下游效应因子.
- 为了确定其他氨基酸是否也通过已识别的通路发出信号.
主要方法:
- 通过使用基于细胞的测试,mTORC1研究了对谷氨酸的感知.
- 利用遗传方法研究蛋白激酶GCN2及其下游标的作用.
- 分析了氨基酸耗尽对mTORC1活动和信号通路的影响.
主要成果:
- 谷氨酸通过蛋白质激酶GCN2间接感知,由阿斯巴拉金的耗尽激活,而不是谷氨酸本身.
- 在一个小时内,GCN2通过Rag GTPases抑制mTORC1,独立于其eIF2α激酶功能.
- GCN2诱导ATF4,导致Ddit4和Sestrin2的上调,导致进一步的mTORC1抑制.
- 大多数其他氨基酸的耗尽也会通过GCN2.2抑制mTORC1.
结论:
- mTORC1通过GCN2间接感知谷氨酸,由阿斯巴拉金耗尽引发.
- GCN2采用不同的机制,包括Rag GTPase调节和ATF4诱导的基因表达,以抑制mTORC1.1.
- 两个独立的系统GCN2和专用氨基酸传感器允许mTORC1感知广泛的氨基酸,确保精确控制细胞生长.
相关概念视频
mTOR Signaling and Cancer Progression
3.9K
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...
3.9K
PI3K/mTOR/AKT Signaling Pathway
4.0K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
4.0K
cAMP-dependent Protein Kinase Pathways
6.6K
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
6.6K
Global Regulatory Systems
74
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
74
Inorganic Nitrogen Assimilation
109
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
109
Stringent Response in E. coli
54
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
54


