関連する実験動画
Updated: Jun 21, 2026

05:52
Reconstitution of Msp1 Extraction Activity with Fully Purified Components
Published on: August 10, 2021
Get3による尻尾固定膜タンパク質認識の構造的基礎
Agnieszka Mateja1, Anna Szlachcic, Maureen E Downing
1Department of Biochemistry & Molecular Biology, The University of Chicago, Gordon Center for Integrative Science, Room W238, 929 East 57th Street, Chicago, Illinois 60637, USA.
Nature
|August 14, 2009
まとめ
研究者らは,Get3 ATPaseが尾に固定されたタンパク質をエンドプラズマ網膜に標的とする方法を明らかにした. 構造的研究は,タンパク質結合と膜挿入のための放出を調節するGet3の核酸依存的構成変化を明らかにします.
科学分野:
- 細胞生物学 細胞生物学
- 構造生物学 構造生物学とは
- タンパク質ターゲティング
背景:
- エンドプラズマ網膜のターゲティングは,膜タンパク質の機能にとって極めて重要です.
- ほとんどの膜タンパク質は,信号認識粒子を介して共同翻訳的ターゲティングを使用します.
- 尾を固定したタンパク質は,この経路をバイパスし,Get3 ATPaseによる翻訳後のターゲティングを必要とします.
研究 の 目的:
- Get3ATPアゼによる尾鎖タンパク質の認識とターゲティングの分子メカニズムを解明する.
- Get3が尾に固定されたタンパク質を結合して放出する方法を理解するために.
主な方法:
- 酵母ゲート3のX線結晶撮影は,異なる核酸結合状態 (核酸無およびADP.AlF ((4) ((-) 結合) で行われる.
- Get3ダイマー状態と構造的再配置の分析.
- 変異分析が尾に固定されたタンパク質の結合に及ぼす影響.
主要な成果:
- 結晶構造は,Get3が異なる"開いた" (ヌクレオチドのない) と"閉じた" (ADP.AlF ((4) ((-) -bound) ダイマー状態に存在することを示している.
- 閉ざされた状態は,ダイマーインターフェイスの水嫌性の溝を特徴としており,これは尾に固定されたタンパク質の結合に不可欠です.
- 開いた状態は,この溝を破壊し,水害性の表面をシールドする再配置された構造を示しています.
結論:
- Get3は,核酸依存の構造変化を利用して,尾を固定したタンパク質の結合と放出を調節します.
- これは,エンドプラズマの網膜に尾を固定したタンパク質の翻訳後のターゲティングのための分子機構を提供します.
関連する概念動画
Tail-anchoring of Proteins in the ER Membrane
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
Lipids as Anchors
In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains the...
GPI Anchoring of Proteins in the ER Membrane
GPI-anchoring is a post-translational, reversible protein modification that is ubiquitous in eukaryotes. Such proteins are primarily present on the exoplasmic leaflet of the plasma membrane.
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Structure of Porins
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel precursors...
Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...

