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
在没有阿尔金林指的情况下,RanGAP调解了GTP水解
Michael J Seewald1, Carolin Körner, Alfred Wittinghofer
1Max-Planck-Institut für molekulare Physiologie, Abteilung Strukturelle Biologie, Dortmund, Germany.
Nature
|February 8, 2002
概括
关氨酸核酸结合蛋白激活蛋白 (GAPs) 通常使用氨酸指机制. 然而,激活Ran GTPase的RanGAP并不采用这种策略.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 关氨酸核酸结合蛋白激活蛋白 (GAPs) 在G蛋白上加速GTP水解.
- "素指"机制是GAP作用的普遍模型,通过Ras和Rho的研究来阐明.
- 核Ras相关的蛋白质Ran调节核细胞质运输和线粒体过程,其与GTP结合的形式由RanGAP和RanBP1.1水解.
研究的目的:
- 为了阐明RanGAP介导的GTP水解的机制.
- 为了研究RanGAP-RanBP1-Ran三元复合函数的结构基础.
- 为了确定RanGAP是否使用保存的阿基尼因手指机制.
主要方法:
- 在基底和过渡状态中确定Ran-RanBP1-RanGAP三元复合物的三维结构.
- 生物化学实验评估GTP水解的机制.
主要成果:
- Ran-RanBP1-RanGAP复合体结构显示,RanGAP不使用阿金指.
- 生物化学数据表明,Ran本身提供了快速GTP水解的核心机械.
- 在Ran内部的催化性谷氨胺残留物对于催化是必不可少的,需要正确的定位.
结论:
- 通过RanGAP介导的GTP水解与在Ras和Rho中看到的已建立的氨酸指纹机制有所不同.
- 兰的内在GTPase活性,由RanGAP和RanBP1促进,对其功能至关重要.
- 结构和生化洞察力强调了精确的催化残留物定位在GTPase调节中的重要性.
相关概念视频
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...
Directionality of Nuclear Transport
Ras-related nuclear protein or Ran is a small G protein that cycles between its GTP and GDP bound states. Ran specific regulators, a Ran GTPase Activating Protein or RanGAP present in the cytosol and a Ran guanine nucleotide exchange factor or RanGEF present inside the nucleus regulate GTP/GDP exchange. A high concentration of GTP inside the cells, in addition to this asymmetric distribution of Ran-specific regulators, leads to a higher RanGTP concentration inside the nucleus. This...
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...
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...

