Gアルファi-Gアルファsキメラは,Gタンパク質の活性化とベータ・ガンマサブユニットの複合相互作用を制御するアルファ鎖ドメインの機能を定義します
S Osawa1, N Dhanasekaran, C W Woon
1Division of Basic Sciences, National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80206.
Cell
|November 16, 1990
まとめ
この研究では,Gタンパク質内のαs活性化ドメインを特定し,N末端がβガンマサブユニット相互作用を調節することを発見しました. これらの発見は,Gタンパク質の信号伝達経路の理解を進める.
科学分野:
- 分子生物学は分子生物学である.
- 細胞シグナリング 細胞シグナリング
- バイオケミストリー バイオケミストリー
背景:
- Gタンパク質 (GsとGi2) は,同類のアルファサブユニットを持つ重要な信号トランスデューサーである.
- Gタンパク質アルファサブユニットの機能領域を理解することは,細胞シグナル伝達の解読の鍵です.
研究 の 目的:
- Gタンパク質アルファサブユニット内のalpha s活性化ドメインを区切る.
- Gタンパク質の機能におけるN末端の調節作用を調査する.
主な方法:
- アルファ i2 残基をアルファ s 配列に置き換えてキメラを構築する.
- アルファsポリペプチドの特定の領域に突然変異を導入する.
- GDP解離と pertussis toxin ADP-ribosylationに対する突然変異の影響を評価する.
主要な成果:
- アルファs配列 (Ile235-Arg356) を含むキメラはアデニリルサイクラスを活性化し,活性化ドメインを局所化する.
- アルファs残留物Glu15-Pro144の変異によりGDP解離率が上昇した.
- N端の変異は,ベータ・ガンマサブユニットによって調節されるプロセスである pertussis toxin ADP-ribosylation に影響を及ぼした.
結論:
- アルファの活性化ドメインは,Ile235-Arg356配列内に位置しています.
- Gタンパク質αサブユニットのN端は,規制領域である.
- このN末端領域は,ベータ・ガンマ子ユニット相互作用とGDP解離を,GTPaseとエフェクタドメインとは無関係に制御する.
関連する概念動画
Activation and Inactivation of G Proteins
11.8K
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...
11.8K
Assembly of Signaling Complexes
6.7K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
6.7K
G Protein-coupled Receptors
18.1K
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
18.1K
G-protein Coupled Receptors
132.7K
G-protein coupled receptors are ligand binding receptors that indirectly affect changes in the cell. The actual receptor is a single polypeptide that transverses the cell membrane seven times creating intracellular and extracellular loops. The extracellular loops create a ligand specific pocket which binds to neurotransmitters or hormones. The intracellular loops holds onto the G-protein.
132.7K
GTPases and their Regulation
10.0K
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,...
Large G-proteins,...
10.0K
GTPases and their Regulation
3.1K
No description available
3.1K


