関連する実験動画
Updated: Jan 28, 2026
08:14
Ammonia Synthesis at Low Pressure
Published on: August 23, 2017
27.3K
尿素循環によるアンモニア代謝のp53調節がポリアミン生物合成を制御する
Le Li1, Youxiang Mao1, Lina Zhao1
1School of Life Sciences, Tsinghua University, Beijing, China.
Nature
|March 8, 2019
まとめ
腫瘍抑制剤p53は尿素循環を調節し,がんの成長を抑制することで,アンモニアのレベルを制御します. アンモニアの蓄積はポリアミンの合成を阻害し 細胞の増殖を遅らせます
科学分野:
- 腫瘍学
- 分子生物学
- 生物化学
背景:
- 癌細胞は高い代謝要求を持ち 過剰なアンモニアを産生します
- アンモニアの除去のメカニズムと腫瘍に蓄積される効果は完全に理解されていません.
研究 の 目的:
- ガンにおけるアンモニア代謝の調節における腫瘍抑制剤p53の役割を調査する.
- ガン細胞の増殖に対するアンモニアの蓄積の影響を明らかにする.
主な方法:
- 尿素サイクル遺伝子のp53の調節 (CPS1,OTC,ARG1) の分析
- アンモニア濃度と腫瘍の成長を評価するインビトロおよびインビボ実験.
- ポリアミン生物合成とODCのmRNA翻訳に対するアンモニアの影響の調査.
主要な成果:
- p53はCPS1,OTC,ARG1を低下させ,アンモニアの排出を減少させ,腫瘍の成長を抑制する.
- これらの尿素サイクル遺伝子のダウンレギュレーションは,相互にp53を活性化します.
- アンモニアの蓄積は,ODC mRNAの翻訳を減少させ,細胞増殖を減少させることで,ポリアミン生物合成を阻害する.
結論:
- p53は,がんにおける尿生成とアンモニア代謝の重要な調節因子である.
- アンモニアは,ポリアミン生物合成と細胞増殖を制御し,p53とアンモニアの代謝と癌の進行を結びつける上で重要な役割を果たします.
関連する概念動画
01:23Urea Cycle
50.1K
The urea cycle describes how liver cells convert ammonia to urea. Ammonia is a toxic waste product of protein catabolism. Land animals must convert ammonia into the less toxic urea which can be safely eliminated by the kidneys through urine. Marine animals excrete ammonia directly, and the surrounding water dilutes the ammonia to safe levels.
50.1K
01:19Regulation of Metabolism
11.6K
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...
11.6K
01:49The Nitrogen Cycle
60.1K
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...
60.1K
01:23Negative Regulator Molecules
38.5K
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
38.5K
01:28The Cell Cycle Control System
5.5K
The cell cycle regulation directs how a cell proceeds from one phase to the next and begins mitosis. The cell cycle control system includes intracellular regulatory molecules and external triggers. They provide "stop" or "advance" signals and operate at specific cell cycle stages termed checkpoints to ensure that a particular process is completed before the cell advances to the next phase.
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and...
Cyclins and cyclin-dependent kinases (Cdks) are the primary cell cycle regulators and...
5.5K
02:11The Cell Cycle Control System
14.2K
The cell cycle is an organized set of events that leads the cell to divide into two daughter cells, each containing chromosomes identical to the parent cell. It is the cell cycle that leads to the formation of an entire organism from a single-cell zygote. Besides, cell division also functions in the renewal or repair of tissues in adult multicellular eukaryotes. For example, in the bone marrow, the stem cells divide to form new blood cells. Although essential for several functions, cell...
14.2K