関連する実験動画
Updated: Jul 20, 2026

10:37
Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
GTP結合の"G"タンパク質が,ゴルギ・スタックを通る輸送に関与する
P Melançon1, B S Glick, V Malhotra
1Department of Biochemistry, Stanford University, California 94305.
Cell
|December 24, 1987
まとめ
グアニン核酸結合タンパク質 (Gタンパク質) は,ゴルギタンパク質の輸送を調節する. GTPガンマSは,受容体ゴルギ膜を遮断することで,この輸送を阻害し,重要な融合段階に影響を及ぼします.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- タンパク質の輸送メカニズム
背景:
- ゴルギ装置は,タンパク質の修正と分類に不可欠です.
- 細胞内タンパク質の輸送は,ゴルギのコンパートメント間の膀の取引に依存しています.
- グアニンヌクレオチド結合タンパク質 (Gタンパク質) は,細胞シグナル伝達とトラフィックのレギュレータとして知られています.
研究 の 目的:
- ゴルギ内タンパク質輸送におけるGタンパク質の役割を調査する.
- GTPガンマSがゴルギの機能に影響を与える特定のメカニズムを解明する.
- GTP gamma S.によって阻害された膀媒介輸送の段階を特定する.
主な方法:
- Golgiコンパートメント間のタンパク質輸送を研究するために,細胞フリーシステムを利用しました.
- 輸送を阻害するためにGTPガンマSとフッ化物/アルミニウムイオンを使用した.
- ドナーと受容体の膜の役割を区別するために,プレインキュベーション実験を行いました.
- 電子顕微鏡を用いて,ゴルギ構造と膀動態を視覚化しました.
主要な成果:
- GTP gamma Sは,ゴルギのコンパートメント間のタンパク質輸送を不可逆的に阻害しました.
- フッ化物/アルミニウムイオンは抑制効果を模倣し,Gタンパク質の関与を示唆した.
- 抑制には,細胞系因子が必要であり,特に受容体ゴルギ膜に影響を及ぼした.
- 膀の結合と融合の間の処理ステップがターゲットとして特定されました.
- 電子顕微鏡では,クラトリンで覆われていない芽と膀が5倍増加したことが示されました.
結論:
- Gタンパク質は,ゴルギ・スタックを通してタンパク質の輸送を調節するために不可欠です.
- GTPガンマSは,受容体膜の膀融合に干渉することによって,ゴルギ伝搬を阻害する.
- この発見は,Gタンパク質のシグナル伝達が,ゴルギの区画的整合性と機能を維持する上で重要な役割を果たしていることを強調しています.
関連する概念動画
GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
Coat Assembly and GTPases
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Golgi Matrix Proteins
Golgi matrix proteins are a group of highly dynamic proteins that maintain the stacked structure of Golgi. These proteins adapt to rapid morphological changes of the Golgi during the cell cycle. During cell division, mild proteolysis removes these connections resulting in Golgi unstacking. In The daughter cells, these proteins help reassemble the unstacked Golgi.
One of the first identified Golgi matrix proteins was GM130, a rod-like protein located in the cis-Golgi. Subsequently, many Golgi...
One of the first identified Golgi matrix proteins was GM130, a rod-like protein located in the cis-Golgi. Subsequently, many Golgi...
Transport Across the Golgi
While it is unclear how molecules move between adjacent Golgi cisternae, it is apparent that the molecules move from cis- cisterna, the entry face, to the trans- cisterna, the exit face. Experiments initially suggested vesicles that bud from one cisterna and fuse with the next cisterna to transport proteins between the cisternae. This vesicular transport model describes the Golgi apparatus as a relatively static structure with a unique enzyme composition in each cisterna. Molecules are...
GTPases and their Regulation
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins.
Large G-proteins, also known...
Large G-proteins, also known...
Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...

