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Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
小G蛋白Cdc42与ACK的GTPase结合域结合的结构
H R Mott1, D Owen, D Nietlispach
1Cambridge Centre for Molecular Recognition, Department of Biochemistry, University of Cambridge, UK.
Nature
|June 9, 1999
概括
在Rho GTPases Cdc42和Rac通过结合因子调节细胞功能. 这项研究揭示了Cdc42和ACK之间的新型复杂结构,详细介绍了特定的结合相互作用.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- Cdc42和Rac是控制细胞细胞骨,分化和增殖的Rho GTPases.
- 它们与下游的效应因子结合,包括像PAK激酶这样的CRIB蛋白和像ACK氨酸激酶和WASP这样的特定蛋白.
- 效应器循环 (交换机I) 是结构动态的,但在Cdc42和Rac之间是相似的,不解释效应器的特异性.
研究的目的:
- 为了确定ACK复合物的Cdc42-GTPase结合域的溶液结构.
- 阐明Cdc42和ACK之间特定相互作用的分子机制.
主要方法:
- 核磁共振 (NMR) 光谱法以确定溶液结构.
- 分析蛋白质-蛋白质相互作用和形状变化.
主要成果:
- 复杂的形成诱导了Cdc42和ACK的显著构造变化.
- 这种相互作用涉及将Cdc42β-sheet与ACK链扩展,类似于Ras/effector相互作用.
- 额外的Cdc42区域有助于效应器结合的特异性,超出了Switch I区域.
结论:
- 在Cdc42和ACK之间阐明了一种新的G蛋白/效应体复合结构.
- 调查结果显示,效应器特异性不仅仅涉及保存的效应器循环.
- 这提供了对Rho GTPase信号通路的调节的见解.
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...
Coat Assembly and GTPases
Vesicles incorporate different coat protein subunits in different cell locations, which changes the properties of the coat, such as the shape and geometry of the transport vesicles. Thus, vesicle coat proteins also play a significant role in cargo selection.
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
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...
Assembly of Signaling Complexes
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,...
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...

