関連する実験動画
Updated: Jun 24, 2026

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RhoC GTPase Activation Assay
Published on: August 23, 2010
RhoファミリーのGTP結合タンパク質Cdc42の構造は,多機能調節体RhoGDIとの複合体である
G R Hoffman1, N Nassar, R A Cerione
1Department of Molecular Medicine, Veterinary Medical Center, Cornell University, Ithaca, New York 14853, USA.
Cell
|February 17, 2000
まとめ
ロー・グアニン核酸分裂阻害剤 (RhoGDI) は,ロ・GTPasesを調節する. 構造分析は,RhoGDI結合がCdc42の活性を抑制し,膜解離を促進することを明らかにし,RhoGDIを明確にします.
科学分野:
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
- 細胞シグナル伝達 細胞信号伝達
背景:
- RhoGDIタンパク質は,RhoファミリーのGTP結合タンパク質の重要な調節体である.
- RhoGTPasesは,細胞骨格組織や細胞運動性などの細胞プロセスにおいて重要な役割を果たします.
研究 の 目的:
- RhoGDIとRho GTPasesの相互作用の構造的基礎を解明する.
- RhoGDIがGTPaseの活性を抑制し,膜結合を調節するメカニズムを理解する.
主な方法:
- X線結晶グラフィーです.
- Cdc42/RhoGDI複合構造の分析 2.6 Å 解像度で.
主要な成果:
- RhoGDIとCdc42の2つの重要な相互作用部位を特定しました.
- RhoGDIのN端はCdc42のスイッチ領域に結合し,GDP解離とGTP水解を阻害する.
- Cdc42のゲラニルゲラニルグループは,RhoGDIの疎水性ポケットに挿入し,膜の放出を促進します.
結論:
- RhoGDIは,Rho GTPasesのネガティブレギュレータとして機能する.
- 構造データは,GTPaseの活性を阻害し,その水性ポケット経由で膜脱離を媒介するRhoGDIの二重の役割を強調しています.
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...
Rab Proteins
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
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...

