腫瘍抑制剤Smad4の突然変異による無活性化のための構造的基礎である
1Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York 10021, USA.
Nature
|July 3, 1997
まとめ
Smad4/DPC4 腫瘍抑制剤について
科学分野:
- 分子生物学は分子生物学である.
- がん研究 がん研究
- 構造生物学 構造生物学とは
背景:
- Smad4/DPC4は重要な腫瘍抑制遺伝子で,臓がんやその他の悪性腫瘍では不活性化されます.
- Smadタンパク質は,TGF-βサイトカインスーパーファミリーのシグナル伝達経路を媒介する.
- Smad4/DPC4は,SMADタンパク質間のヘテロオリゴメリゼーションに不可欠であり,信号伝達において中心的な役割を果たします.
研究 の 目的:
- Smad4/DPC4腫瘍抑制剤のC端領域 (CTD) の結晶構造を決定する.
- Smad4/DPC4機能の構造的基礎と癌における無活性化を解明する.
主な方法:
- 2.5 Aの解像度のX線結晶撮影により,Smad4/DPC4 CTD.の構造を決定する.
- 決定された構造との関係における腫瘍由来ミッセンスの変異の分析.
主要な成果:
- Smad4/DPC4 CTDは,保存されたタンパク質-タンパク質インターフェースを介して安定した結晶学トリマーを形成します.
- がんに関連したミスセンス変異のほとんどは,このトリメア界面にマッピングされています.
- これらの変異は,Smad4/DPC4のホモオリゴメリゼーションをインビトロとインビボの両方で破壊することが示されました.
結論:
- Smad4/DPC4 CTDのトリメアアセットは,シグナリング機能に極めて重要です.
- Smad4/DPC4の腫瘍起源の変異は,この重要なトリメア構造を破壊し,シグナル伝達の障害を引き起こす.
- この構造的メカニズムを理解することで,臓がんの発症の洞察が得られます.
関連する概念動画
Mismatch Repair
Overview
Abnormal Proliferation
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
Mismatch Repair
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
Loss of Tumor Suppressor Gene Functions
Tumor suppressor genes are normal genes that can slow down cell division, repair DNA mistakes, or program the cells for apoptosis in case of irreparable damage. Hence, they play an essential role in preventing the proliferation of damaged cells.
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...
When the tumor suppressor genes develop mutations or are lost, cells start growing out of control, leading to cancer. However, a single functional copy of the tumor suppressor gene is enough for the cells to maintain their normal functions and cell...


