関連する実験動画
Updated: May 11, 2026

10:37
Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
ガルファサブユニットによるヌクレオチド放出のGoLoco誘発阻害のための構造的決定因子
Randall J Kimple1, Michelle E Kimple, Laurie Betts
1Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Nature
|April 27, 2002
まとめ
GoLocoモチーフを持つ調節タンパク質は,Galphaサブユニットと結合し,Gタンパク質解離を維持する. 構造分析は,GoLocoトライアードを含む重要な相互作用を明らかにします.
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
- 細胞シグナリング
背景:
- ヘテロトリメリックGタンパク質は,細胞表面受容体シグナル伝達を媒介する.
- Gタンパク質の活性化には,GalphaサブユニットであるGTPの結合と解離が含まれます.
研究 の 目的:
- GoLocoモチーフ媒介のGタンパク質調節の構造的基礎を解明する.
- GoLocoタンパク質がGalphaサブユニットとどのように相互作用するかを理解するために.
主な方法:
- ガルファのX線結晶学 ((i1) GDP bound to RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region. GDP bound to RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region. RGS14 GoLoco region.
- ドメイン交換実験です.
主要な成果:
- GoLocoモチーフとGalphaの間の詳細な構造的接触 ((i1) GDP.
- 保存されたAsp/Glu-Gln-Argトライアードの核酸結合ポケット相互作用における役割の特定.
- ガルファの全螺旋ドメインとC端末の残留物がゴロコ特異性を決定する証拠.
結論:
- GoLocoモチーフは,G-タンパク質の信号伝達を調節するために,Galphaサブユニットと直接相互作用します.
- 構造的洞察は,RGSタンパク質によるGタンパク質の調節を理解するための基礎を提供します.
関連する概念動画
G-protein Coupled Receptors
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.
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...
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...
GPCR Desensitization
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...

