栄養素としての細胞外タンパク質の利用は,mTORC1によって抑制される
Wilhelm Palm1, Youngkyu Park2, Kevin Wright2
1Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
Cell
|July 7, 2015
まとめ
哺乳類の細胞は,マクロピノサイトーシスを利用して,細胞外タンパク質から必須アミノ酸を得ることができます. mTORC1を阻害すると,細胞がこの栄養源に依存するときにタンパク質の分解を促すことで細胞増殖が促進されます.
科学分野:
- 細胞生物学 細胞生物学
- メタボリック経路は
- がん研究 がん研究
背景:
- 哺乳類の細胞は,主にグルコースとアミノ酸を代謝する.
- 細胞外タンパク質のRas誘発のマクロピノサイトーシスは,変形した細胞におけるグルタミン依存度を軽減することができます.
研究 の 目的:
- タンパク質マクロピノサイトーシスが必須アミノ酸の源として役立つかどうかを調査する.
- アミノ酸供給のために細胞外タンパク質を利用する細胞におけるmTORC1活性化の役割を理解する.
- 癌におけるmTORC1の調節による治療の可能性を調査する.
主な方法:
- 細胞外タンパク質を内部化するためにマクロピノサイトーシスを利用した.
- タンパク質の溶解体分解を評価した.
- mTORC1の活性化と細胞増殖を測定した.
- 抑制されたmTORC1活性 in vitroおよびin vivoモデル (腫瘍).
主要な成果:
- タンパク質マクロピノサイトーシスは,細胞の生存に不可欠なアミノ酸を提供する.
- 細胞外タンパク質によるmTORC1の活性化は生存を維持するが,増殖を抑制する.
- mTORC1の阻害は,内細胞化タンパク質の分解を促進する.
- mTORC1の阻害は,栄養素が不足した状態や腫瘍における細胞増殖を助長する.
結論:
- mTORC1の活性化は,タンパク質の消費を防ぐことによって,細胞の成長をフリーアミノ酸の利用に結びつけます.
- mTORC1の活性を調節することは,特に栄養素が少ない腫瘍の微小環境において,がんに対する潜在的な治療戦略を提供します.
関連する概念動画
mTOR Signaling and Cancer Progression
5.1K
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...
5.1K
mTOR Signaling and Cancer Progression
1.7K
1.7K
PI3K/mTOR/AKT Signaling Pathway
6.4K
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...
6.4K
Overview of Protein Metabolism
4.7K
Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
4.7K
Mitogens and the Cell Cycle
8.4K
Mitogens and their receptors play a crucial role in controlling the progression of the cell cycle. However, the loss of mitogenic control over cell division leads to tumor formation. Therefore, mitogens and mitogen receptors play an important role in cancer research. For instance, the epidermal growth factor (EGF) - a type of mitogen and its transmembrane receptor (EGFR), decides the fate of the cell's proliferation. When EGF binds to EGFR, a member of the ErbB family of tyrosine kinase...
8.4K
Protein Networks
4.7K
An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions.
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
4.7K


