相关实验视频
Updated: May 11, 2026

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Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
戈洛科诱导的核酸释放受Galpha亚单元的抑制的结构决定因素
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
概括
具有GoLoco动图的调节蛋白与Galpha亚单元结合,维持G蛋白解离. 结构分析揭示了关键的相互作用,包括GoLoco三位一体.
科学领域:
- 分子生物学分子生物学
- 结构生物学是结构生物学.
- 细胞信号传递 细胞信号传递
背景情况:
- 异构三级G蛋白调解细胞表面受体信号传递.
- G-蛋白激活涉及Galpha亚单元的GTP结合和解离.
研究的目的:
- 阐明GoLoco基因介导的G蛋白调节的结构基础.
- 了解GoLoco蛋白质如何与Galpha子单元相互作用.
主要方法:
- 加尔法的X射线晶体学(i1) GDP与RGS14 GoLoco地区相结合.
- 域互换实验. 域互换实验.
主要成果:
- 在GoLoco图案和Galpha之间详细的结构联系.GDP.
- 确定保存的Asp/Glu-Gln-Arg三合体在核酸结合口袋相互作用中的作用.
- 有证据表明,Galpha全螺旋域和C端残留物决定了GoLoco的特异性.
结论:
- 戈洛科基因直接与加尔法子单元相互作用,调节G蛋白信号传递.
- 结构洞察力为了解RGS蛋白质对G蛋白调节的理解提供了基础.
相关概念视频
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...

