在Ras上,Grb2调解了依赖于EGF的关氨酸核酸交换的激活
N W Gale1, S Kaplan, E J Lowenstein
1Cold Spring Harbor Laboratory, New York 11724.
Nature
|May 6, 1993
概括
Grb2蛋白通过增加Ras激活来增强表皮生长因子受体 (EGFR) 信号传递. 这种蛋白质复合体的形成将EGFR与Ras联系起来,调节细胞生长途径.
科学领域:
- 细胞生物学 细胞生物学
- 分子信号通道的分子信号通道.
- 信号传导是指信号的传导方式.
背景情况:
- 像表皮生长因子 (EGF) 受体一样的受体氨酸激酶 (RTK) 激活Ras蛋白.
- 连接RTK与Ras的精确机制仍然不完全理解.
- Grb2是一种具有Src-homology (SH) 2和3域的蛋白质,涉及RTK-Ras信号传递.
研究的目的:
- 阐明 Grb2 在表皮生长因子 (EGF) 诱导的 Ras 激活中的作用.
- 为了研究Grb2如何影响Ras.上的瓜核酸换率.
- 了解Grb2,关氨酸核酸交换因子和EGF受体之间的相互作用.
主要方法:
- 细胞系统中Grb2的过度表达.
- 测量Ras激活和基因激活蛋白激酶 (MAPK) 活性.
- 分析涉及Grb2,瓜核酸交换因子和EGF受体的蛋白质复合体形成.
主要成果:
- 过度表达Grb2增强了EGF诱导的Ras和MAPK的激活.
- Grb2 增强了在 Ras.上氨酸核酸交换的速度.
- 细胞Grb2形成了一个复杂的Ras氨酸核酸交换因子,与激活的EGF受体结合.
结论:
- Grb2充当关键的调解者,将激活EGF受体与Ras.
- Grb2 增强了 Ras 关氨酸核酸交换活性,从而促进了 Ras 激活.
- 这种机制使得氨酸激酶能够有效调节细胞Ras活动.
相关概念视频
Enzyme-linked Receptors
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Enzyme-linked Receptors
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
The Ras Gene
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 superfamily...
Ras is a superfamily...
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:
G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
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...


