関連する実験動画
Updated: Jul 10, 2026

09:58
RhoC GTPase Activation Assay
Published on: August 22, 2010
RhoとRasファミリーのGTPase活性化剤との関連性
J Settleman1, C F Albright, L C Foster
1Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge 02142.
Nature
|September 10, 1992
まとめ
p190タンパク質は,GTPasesのrhoファミリーに特化したGTPase活性化タンパク質 (GAP) として作用する. この発見は,細胞応答におけるrasとrhoの信号伝達経路の間の潜在的なリンクを示唆しています.
科学分野:
- 分子生物学は分子生物学である.
- 細胞シグナル伝達 細胞信号伝達
- バイオケミストリー バイオケミストリー
背景:
- ラス関連のGTPアゼは,細胞サイクルや分化などの多様な細胞機能に不可欠です.
- GTP酵素活性化タンパク質 (GAPs) は,GTP酵素の水解を刺激することによって,GTP酵素の活性化を調節する.
- Ras-GAPは,成長因子刺激細胞でp190と複合体を形成する.
研究 の 目的:
- p190.0のGTPase活性化タンパク質 (GAP) の活性について調査する.
- どのGTPaseファミリー (ras, rho, rab) がp190.0によって調節されているかを判断する.
- Ras-GAP/p190複合体の機能的影響を調査する.
主な方法:
- 再結合されたp190タンパク質を浄化しました.
- ras, rho, rab GTPasesに対するp190のGAP活性をテストするために,in vitroアッセイが行われました.
- Ras-GAPとp190の間のタンパク質複合体の形成は,細胞の文脈で分析されました.
主要な成果:
- p190は,ロ族のメンバーに対する特定のGTPase活性化タンパク質 (GAP) の活性を示した.
- p190は,rasまたはrabファミリーのGTPasesに有意なGAP活性を示さなかった.
- p190のカーボキシ末端領域は,他の既知のGAPと同質性を共有しています.
結論:
- p190は,rho GTPasesの特定のGAPとして機能します.
- Ras-GAPとp190の相互作用は,rasとrhoの信号伝達経路を橋渡しする可能性がある.
- この相互作用は,成長因子に対する細胞の反応に決定的な役割を果たす可能性があります.
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...
The Ras Gene
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Ras is a superfamily...
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...
Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
Small GTPases - Ras and Rho
Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
Three regulatory proteins control their activity:
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...

