κB-Ras蛋白质是快速交换的GTPases,并通过核酸独立结合Ral GTPase激活蛋白质复合体来起作用
René Rasche1, Lisa Helene Apken2, Esther Michalke2
1Institute of Biochemistry, University Münster, Germany.
FEBS letters
|April 11, 2024
概括
κB-Ras GTPases,尽管与Ras的结构差异,但表现出水解活性,并且主要与GTP结合. 它们在Ral和NF-κB信号传递中的瘤抑制功能独立于核酸结合和开关机制.
科学领域:
- 分子生物学分子生物学
- 细胞信号传递 细胞信号传递
- 在瘤学瘤学.
背景情况:
- κB-Ras GTPases是Ras类蛋白质,具有独特的序列动图.
- 它们通过抑制Ral GTPase和NF-κB信号传递而起瘤抑制作用.
- 它们的确切作用机制在很大程度上仍未被描述.
研究的目的:
- 研究 κB-Ras GTPases 的生化特性和功能机制.
- 确定核酸结合和水解在 κB-Ras活动中的作用.
- 分析与瘤相关的 κB-Ras 突变对其功能的影响.
主要方法:
- 生物化学测试以评估GTPase的水解活性和核酸结合亲和力.
- 在生物体内进行细胞研究以确定 κB-Ras 的核酸结合状态.
- 对Ral GTPase激活蛋白 (RalGAP) 的结合和稳定性进行 κB-Ras突变的分析.
主要成果:
- 与预测相反, κB-Ras GTPases具有显著的水解活性.
- 它们具有较低的核酸亲和力,在细胞环境中主要与GTP结合.
- 核酸结合会影响 κB-Ras 的稳定性,但对 RalGAP 的结合并非必不可少.
结论:
- κB-Ras作为一个快速循环的GTPase.
- 它在调节RalGAP/Ral信号传递中的瘤抑制作用独立于核酸结合和构造性切换.
- 了解 κB-Ras 功能,可以了解癌症信号通路.
相关概念视频
Small GTPases - Ras and Rho
3.9K
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:
3.9K
The Ras Gene
6.2K
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a...
Ras is a...
6.2K
Rab Proteins
3.9K
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...
3.9K
GTPases and their Regulation
8.3K
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,...
8.3K
Rab Cascades
2.6K
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
2.6K
Activation and Inactivation of G Proteins
7.1K
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...
7.1K


