ヌクレオシドトランスポーターの多段階のエレベーターのような移行を視覚化
Marscha Hirschi1, Zachary Lee Johnson1, Seok-Yong Lee1
1Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, North Carolina 27710, USA.
Nature
|April 21, 2017
まとめ
研究者らは,核酸輸送器のエレベーターメカニズムの中間のステップを視覚化しました. これは,膜輸送の詳細な形状の経路を明らかにし,トランスポーター機能に関する新しい洞察を提供します.
科学分野:
- 生物化学
- 構造生物学
- 膜輸送
背景:
- メンブラントランスポーターは,交互のアクセスを通して細胞膜を横断する基板の移動を容易にする.
- エレベーターメカニズムは,トランスポートドメインが膜を横断する新興モデルです.
- 以前の研究では,このメカニズム内の構造的移行に関する詳細な構造情報が欠けていました.
研究 の 目的:
- 膜輸送におけるエレベーターメカニズムの構成経路を解明する.
- 濃縮性核酸トランスポーターの中間状態を特徴づける.
主な方法:
- トランスポーターの構造を決定するために,X線結晶学が採用されました.
- 内向き,中間,外向きの状態の構造が解明されました.
- 複数の中間形状が分析された.
主要な成果:
- クリスタル構造は 輸送領域の様々な段階を 捕捉した
- 多数の中間形状は 形状転換の詳細な軌道を明らかにした.
- 輸送領域内の国家に依存する構成的変化が特定されました.
結論:
- この研究は,静的な最終状態を超えて,エレベーターメカニズムの包括的な軌道を提示しています.
- 中間の形状に関する詳細な構造の洞察は,膜輸送器のダイナミクスの理解を進める.
- 発見は,ヌクレオシドトランスポーターにおけるエレベーターのような運動のメカニズム的基礎を提供します.
関連する概念動画
Secondary Active Transport
139.2K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
139.2K
Secondary Active Transport
11.8K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
11.8K
Protein Translocation Machinery on the ER Membrane
7.1K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
7.1K
The Movement of Organelles and Vesicles
6.9K
In eukaryotic cells, cytoskeletal filaments such as actin, microtubules, and intermediate filaments form a mesh-like cytoskeletal network. These filaments serve as tracks for transporting cellular cargo. Specialized motor proteins use the chemical energy stored in adenosine triphosphate (ATP) for this transport. During interphase, microtubules are polarized, with the plus-end towards the cell periphery and the minus-end towards the cell center. Two microtubule-associated motor proteins,...
6.9K
Primary Active Transport
16.5K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would...
16.5K
Primary Active Transport
202.9K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction...
202.9K


