単純な構造は,IGF-II/マノース6リン酸受容体のGタンパク質活性化機能をコードする
T Okamoto1, T Katada, Y Murayama
1Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Japan.
Cell
|August 24, 1990
まとめ
インスリン型の成長因子II/マノース6リン酸受容体 (IGF-II/man6PR) は,Gi-2Gタンパク質を直接活性化します. この相互作用には特定の受容体セグメントが不可欠であり,Gタンパク質結合受容体と似ています.
科学分野:
- 細胞の信号伝達経路は,
- Gタンパク質に結合した受容体.
- 受容体-リガンドの相互作用
背景:
- インスリン型の成長因子II/マノース6リン酸受容体 (IGF-II/man6PR) は,Gタンパク質と相互作用することが知られている.
- IGF-II/man6PRとGタンパク質,特にGi-2との相互作用の正確なメカニズムについては,さらなる解明が必要である.
研究 の 目的:
- IGF-II/man6PRの特定の領域を特定し,Gi-2 Gタンパク質の活性化に責任を負います.
- この活性化セグメントの機能的性質と,様々なGタンパク質との相互作用を特徴づける.
- 受容体のGi-2活性化機能におけるこのセグメントの重要な役割を確認するために.
主な方法:
- 人間のIGF-II/man6PR.から特定のセグメント (残留物2410-2423) のペプチド合成.
- 異なるGタンパク質 (Gi-1,Gi-2,Gi-3,Go,Gs) と低分子量Gタンパク質を活性化するセグメントの能力をテストするインビトロアッセイ.
- セグメントの修正は,受容体トランスメブラン領域の一部に接続することで,潜在性を評価します.
- 特定のセグメントを標的とした抗体を用いてGi-2の活性化をブロックする抑制測定法.
主要な成果:
- 人間のIGF-II/man6PR (残基2410-2423) の一部が,Gi-2 Gタンパク質を直接活性化しています.
- セグメントの活性化には,Gi-2 > Gi-1 ≈ Gi-3 > Goという階層があり,Gsや小さなGタンパク質には影響はありません.
- セグメントの主要な構造は,その機能に不可欠であり,この機能は,受容体のトランスメブラン領域とリンクされたときに強化されます.
- セグメントに対する抗体は,IGF-II/man6PR.のGi-2活性化機能を効果的にブロックしました.
結論:
- IGF-II/man6PR内の特定のアミノ酸セグメントは,Gi-2 Gタンパク質の活性化に直接責任を負う.
- このセグメントは,Gi-2を活性化するGタンパク質結合受容体の機能を模倣しています.
- 特定されたセグメントは,受容体の信号伝達経路において重要な役割を果たし,細胞通信におけるその重要性を強調しています.
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