ジェム (Gem):Ras族に属する,誘導された,即時の初期のタンパク質
まとめ
新しいグアノシン三リン酸 (GTP) 結合タンパク質であるGemがT細胞で特定されました. ゲム不調は細胞増殖を阻害し,信号伝達と細胞周期調節における役割を示唆する.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- ゲム (Gem) と呼ばれる新しいグアノシン三リン酸 (GTP) 結合タンパク質は,ヒトの周辺血液T細胞からクローン化されました.
- GemとRadはRasに関連したGTP結合タンパク質の新しい家族を形成し,RadはII型糖尿病と関連しています.
- このタンパク質ファミリーは,特定のGTP結合モチーフと膜結合ドメインを含むユニークな構造特性を有しています.
研究 の 目的:
- ゲムタンパク質の特徴,その発現,および細胞プロセスにおける機能について説明する.
- ミトゲン誘発のT細胞活性化におけるGEMの役割を調査する.
- 細胞増殖と信号伝達経路におけるGEMの潜在的な関与を探求する.
主な方法:
- ミトゲン誘発型T細胞からジェム遺伝子をクローン化.
- 人間のT細胞と3T3細胞におけるGEMの一時的な発現.
- ゲムタンパク質のリン酸化と亜細胞局所化の分析.
- 細胞増殖に対する規制解除されたGem発現の効果の評価.
主要な成果:
- Gemは35キロダルトンのGTP結合タンパク質で,T細胞で発現しています.
- 宝石タンパク質はチロシン残基にリン酸化され,ミトゲン刺激により血と結合する.
- 異常なGem発現は,正常な3T3細胞と変異した3T3細胞の両方の増殖を停止します.
結論:
- Gemは,レギュレータタンパク質として機能し,プラズマ膜の受容体媒介信号伝導に潜在的に関与しています.
- Gemは細胞増殖を調節する上で重要な役割を果たします.
- Gemのシグナル伝達経路に関するさらなる研究は,T細胞の活性化やII型糖尿病のような疾患についての洞察を提供することができる.
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...
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...
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...
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...


