結晶構造と,その効果体であるフォスホイノシチド3-キナーゼガンマにRas結合の機能分析
M E Pacold1, S Suire, O Perisic
1MRC Laboratory of Molecular Biology Hills Road CB2 2QH, Cambridge, United Kingdom.
Cell
|January 4, 2001
まとめ
ラスタンパク質は,がん細胞の生存に不可欠なフォスホイノシチド3キナーゼガンマ (PI3Kgamma) を直接活性化します. 構造分析は,この活性化に不可欠な特定の結合相互作用を明らかにし,新しい治療標的を提供している.
科学分野:
- 分子生物学は分子生物学である.
- セルラー・シグナリング
- 構造生物学 構造生物学とは
背景:
- フォスホイノシチド3キナーゼ (PI3K) のRas活性化は,変形した細胞の生存に不可欠です.
- RasとPI3Kの間の直接的な分子相互作用を理解することは,癌細胞の増殖を解読する鍵です.
研究 の 目的:
- Ras.によってPI3Kガマの直接活性化メカニズムを調査する.
- Ras-PI3Kガマ相互作用の構造的基礎を決定する.
- これらの相互作用ががん細胞生存に及ぼす影響を調査する.
主な方法:
- H-Ras G12VとGTPgammaSを搭載したH-Rasを用いた vivoおよびin vitro活性化アッセイ.
- PI3Kgamma/Ras.GMPPNP複合体の結晶構造の決定. PI3Kgamma/Ras.GMPPNP複合体の結晶構造の決定. PI3Kgamma/Ras.GMPPNP複合体の結晶構造の決定. PI3Kgamma/Ras.GMPPNP複合体の結晶構造の決定.
- サイト・ディレクテッド・ミュータジェネシス (サイト・ディレクテッド・ミュータジェネシス) により,重要な相互作用領域を分析する.
主要な成果:
- PI3KガマはH-Ras.によって強く直接活性化されます.
- 結晶構造は,PI3Kガマ結合のためのスイッチIとスイッチII領域を通じてRasを位置づけている重要なループを明らかにしています.
- ミュタゲネシスは,これらのRas領域がPI3Kガマ相互作用の必要性を確認し,触媒ドメインと直接接触する.
結論:
- 特定の構造的相互作用が Ras.によってPI3Kガマの直接活性化を媒介する.
- これらの発見は,PI3Kalpha.と潜在的に共有される保存された活性化メカニズムを示唆しています.
- 観察されたPI3Kgammaの形状の変化は,Ras媒介活性化におけるアロステリック成分を示し,がん治療に関連しています.
さらに関連する動画
07:49Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods
Published on: July 17, 2019
5.7K
06:44Author Spotlight: Integrating BRET-Based Assays and Rare Mutation Analysis to Decipher RAF Kinase Regulation in Live Cells
Published on: March 1, 2024
1.9K
関連する概念動画
Protein Kinases and Phosphatases
12.1K
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
12.1K
The Ras Gene
5.7K
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...
5.7K
Amplifying Signals via Enzymatic Cascade
15.3K
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze...
15.3K
Small GTPases - Ras and Rho
4.4K
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:
4.4K
MAPK Signaling Cascades
7.3K
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...
7.3K
IP3/DAG Signaling Pathway
12.5K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
12.5K
