通过氨基酸对mTORC1的动态调节的结构基础
Max L Valenstein1,2,3,4, Maximilian Wranik5,6,7, Pranav V Lalgudi2,3
1Department of Medicine, Massachusetts General Hospital, Boston, MA, USA.
Nature
|August 20, 2025
概括
对于生长至关重要的拉巴胺素复合物1 (mTORC1) 途径的机械性标受营养传感器的调节. 这项研究揭示了氨基酸传感器Sestrin2和CASTOR1如何与GATOR2复合体结合和调节,控制mTORC1的激活.
科学领域:
- 细胞生物学
- 分子生物学
- 生物化学
背景情况:
- 拉巴胺素复合物1 (mTORC1) 途径的机械性标调节基于营养的细胞生长.
- 氨基酸传感涉及GATOR复合体,包括GATOR2,它与白素传感器 (Sestrin1/2) 和素传感器 (CASTOR1) 相互作用.
- 在氨基酸结合时,GATOR2的传感器调节和释放的精确机制以前是未知的.
研究的目的:
- 阐明氨基酸传感器调节GATOR2复合物的结构机制.
- 了解氨基酸如何触发传感器与GATOR2的结合和解离.
- 揭示控制营养物质依赖的mTORC1激活的异质机制.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定与Sestrin2或CASTOR1结合的GATOR2的结构.
- 在Sestrin2和CASTOR1中对apo-Sestrin2和氨基酸诱导的重排的结构分析.
- 生物化学测试以评估传感器结合对GATOR2功能和mTORC1激活的影响.
主要成果:
- 这些结构揭示了Sestrin2和CASTOR1在GATOR2上的不同,不重叠的结合点.
- 这些结合部位的破坏选择性地损害了mTORC1对单个氨基酸的感知.
- 氨基酸结合诱导了传感器的结构重组,导致它们与GATOR2分离,并限制了GATOR2的动态WDR24β螺旋.
结论:
- 这项研究揭示了氨基酸充足性向GATOR2传递的全性机制.
- 在氨基酸结合时,传感器和GATOR2的结构变化对营养依赖的mTORC1激活至关重要.
- 这些发现为了解营养感应和生长调节提供了分子基础.
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
3.9K
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...
3.9K
Covalently Linked Protein Regulators
7.1K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
7.1K
MAPK Signaling Cascades
6.0K
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
6.0K
Regulation of Metabolism
9.9K
Cellular needs and conditions vary from cell to cell and change within individual cells over time. For example, the required enzymes and energetic demands of stomach cells are different from those of fat storage cells, skin cells, blood cells, and nerve cells. Furthermore, a digestive cell works much harder to process and break down nutrients during the time that closely follows a meal compared with many hours after a meal. As these cellular demands and conditions vary, so do the amounts and...
9.9K
Interactions Between Signaling Pathways
6.4K
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
6.4K


