関連する実験動画
Updated: Jul 17, 2026

09:05
Cycloheximide Chase Analysis of Protein Degradation in Saccharomyces cerevisiae
Published on: April 18, 2016
ユビキチンに依存するc-Junの分解は,デルタドメインによって媒介される
M Treier1, L M Staszewski, D Bohmann
1European Molecular Biology Laboratory, Differentiation Programme, Heidelberg, Federal Republic of Germany.
Cell
|September 9, 1994
まとめ
ユビキチンに依存するタンパク質分解システムは,分解のためにc-Junをターゲットにしますが,v-Junではありません. c-Junのデルタドメインは,このユビキチン化と分解を媒介し,新しい腫瘍生成経路を示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- 腫瘍学 腫瘍学
背景:
- ユビキチンに依存するタンパク質分解システムは,タンパク質の周回を調節する.
- c-Junは細胞増殖と分化に関与する転写因子です.
- v-Junは,c-Junから派生したウイルス性オンコタンパク質です.
研究 の 目的:
- c-Jun分解におけるユビキチン依存タンパク質分解システムの役割を調査する.
- c-Junとv-Junの分解経路を比較するために.
- c-Junとv-Junの安定性の分子決定因子を特定するために.
主な方法:
- インビトロユビキチネーションアッセイ.
- 分子的にタグ付けされたユビキチンとc-Jun.を使用したインビボアッセイ.
- c-Junとv-Junのサイト指向型変異.
- タンパク質の半減期測定.
- c-Jun配列をレポータータンパク質 (β-ガラクソシダゼ) に機能的に転送する.
主要な成果:
- c-Junは効率的にマルチウビキチン化されていますが,v-Junはそうではありません.
- v-Junは,c-Junと比較して半減期が長くなります.
- c-Junのデルタドメイン (27アミノ酸) は,そのユビキチン化と分解を担当しています.
- v-Junにおけるデルタドメインの削除は,ユビキチン化および分解に対する耐性を授与する.
- デルタドメインは,他のタンパク質に転送されると,シス作用のユビキチン化および分解信号として作用します.
結論:
- c-Junのデルタドメインは,そのユビキチン依存性分解の決定的決定因子である.
- ユビキチン媒介型タンパク質分解から脱出することは,v-Jun.の腫瘍性潜在性に寄与する.
- この研究は,タンパク質の分解経路と腫瘍生成を結びつける新しいメカニズムを明らかにしています.
関連する概念動画
The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important amongst these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...
Regulated Protein Degradation
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Anaphase Promoting Complex
The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...
Export of Misfolded Proteins out of the ER
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
Regulated Protein Degradation
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
The Proteasome
Eukaryotic cells can degrade proteins through several pathways. One of the most important among these is the ubiquitin-proteasome pathway. It helps the cell eliminate the misfolded, damaged, or unwarranted cytoplasmic proteins in a highly specific manner.
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...

