関連する実験動画
Updated: Jul 5, 2026

10:13
Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding
Published on: June 9, 2017
小型GTPase Rab6に対する再結合抗体は,コンフォームセンサとして使用されます
Clement Nizak1, Solange Monier, Elaine del Nery
1CNRS UMR144, Institut Curie, 26 rue d'Ulm, F75248 Paris Cedex 05, France.
まとめ
研究者らは,抗体ファグディスプレイを用いた分子構成センサを開発し,グアノシントリフォスファターゼ (GTPase) Rab6.6を追跡した. この方法は,細胞内のRab6-GTPを可視化し,輸送中介物質の調節におけるその役割を明らかにし,分子ダイナミクスを研究するための新しいツールを提供します.
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
- バイオケミストリー バイオケミストリー
背景:
- Rab6は小さなGTPaseであり,膜の流れを調節し,異なる形状状態に存在する.
- Rab6-GTPの細胞プロセスにおけるダイナミクスを理解することは,輸送機構の解読に不可欠です.
研究 の 目的:
- GTPaseの活性 in vivoを研究するための新しい分子構成センサを開発する.
- Rab6.6のグアノシン三酸塩 (GTP) に結合した状態に対する構成特有の抗体を生成する.
- Rab6-GTPの細胞輸送における局所化と機能を調査する.
主な方法:
- 抗体ファグディスプレイは,Rab6.6のGTP結合コンフォームに特異的な再結合抗体を生成するために使用されました.
- 形状特異抗体は,固定細胞内のRab6-GTPを特定するために使用されました.
- 緑色光タンパク質 (GFP) のタグ付けと細胞内発現は,Rab6-GTPの in vivo トラッキングを可能にしました.
主要な成果:
- この研究では,Rab6-GTP.に対するコンフォーム特異抗体を成功裏に生成しました.
- Rab6-GTPは,ゴルギ装置と輸送中介物質に局在していた.
- Rab6の活動は,輸送中介物質の幾何学を調節することが示されました.
結論:
- 抗体ファグディスプレイは,分子構成センサを作成するための実行可能なアプローチです.
- 開発されたセンサーは,膜トラフィックにおけるRab6の機能に関する洞察を提供します.
- この方法論は,他の構成動的分子のためのセンサーを生成するために拡張できます.
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...
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...
Transducer Mechanism: G Protein–Coupled Receptors
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical, 7TM, or...
GPCRs are also called heptahelical, 7TM, or...

