関連する実験動画
Updated: Jul 9, 2026

09:12
MISSION LentiPlex Pooled shRNA Library Screening in Mammalian Cells
Published on: December 21, 2011
セマフォリン4D受容体プレキシン-B1は,R-RasのGTPase活性化タンパク質である
Izumi Oinuma1, Yukio Ishikawa, Hironori Katoh
1Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
まとめ
セマフォリン4D受容体であるプレキシン-B1は,R-Ras GTPase活性を活性化します. この相互作用は,セマフォリン4Dが誘発した神経細胞における排斥性軸索誘導シグナル伝達に極めて重要です.
科学分野:
- 神経科学は神経科学である.
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
背景:
- プレキシンは,セマフォリンと結合する細胞表面受容体であり,細胞の結合と移動を調節する.
- R-RasのようなRasスーパーファミリータンパク質は,細胞結合とニューライトの増殖に不可欠です.
研究 の 目的:
- Plexin-B1とR-Ras.との相互作用を調査する.
- セマフォリン4D媒介のニューロン誘導におけるプレキシン-B1-R-Ras信号伝達の役割を明らかにする.
主な方法:
- Plexin-B1とR-Ras.の間の直接的な相互作用を調査しました.
- プレキシン-B1-R-Ras複合体の形成におけるRnd1の役割を調べました.
- この複合体のR-Ras GTPase活性に対する効果を評価した.
- ヒポキャンパスのニューロンにおけるSema4D誘発の成長の崩壊を研究した.
主要な成果:
- Plexin-B1は,R-Ras.のGTPase活性を直接刺激する.
- この活性化には,Plexin-B1とRnd1.1の相互作用が必要です.
- プレキシン-B1-Rnd1複合体はR-Rasの活動をダウン調節する.
- このダウンレギュレーションは,Sema4Dが誘発した成長コンの崩壊に不可欠です.
結論:
- Plexin-B1は,R-Ras.のGTPase活性化タンパク質として作用する.
- プレキシン-B1は,R-Ras調節によるSema4D誘発の排斥性軸索誘導シグナル伝達を媒介する.
- この経路は,神経細胞の発達と誘導に不可欠です.
関連する概念動画
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...
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...
Cell Polarization by Rho Proteins
Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...
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:
MAPK Signaling Cascades
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
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...

