物体が動く方法:分子モータータンパク質のフードの下に目を向ける
1Howard Hughes Medical Institute and Department of Cellular and Molecular Pharmacology, University of California, 513 Parnassus Avenue, San Francisco, CA 94143, USA. vale@phy.ucsf.edu
まとめ
細胞機能に不可欠なキネシンやミオシンのような分子モーターは,共通の構造を共有しています. このモジュール型の設計により,特定の生物学的役割に最適化された多様な運動機能が可能になります.
科学分野:
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
- 細胞力学 細胞力学
背景:
- キネシンとミオシンモーターは,細胞内交通,細胞分裂,筋肉収縮などの重要な細胞プロセスを駆動します.
- 歴史的に,微小管ベースのキネシンとアクチンベースのミオシンには,異なるメカニズムが提案されました.
- 最近の研究は,それらの基本的な動作原理の収束を示しています.
研究 の 目的:
- キネシンとミオシンの分子モーターの構造とメカニズムに関する共通の原理を解明する.
- 保存されたコア構造が様々な機械増幅器とどのように相互作用するかを探求する.
- 分子モーターの機能的多様性の基礎を理解する.
主な方法:
- キネシンとミオシンモータータンパク質の比較構造分析.
- アデノシン三リン酸 (ATP) の水解とエネルギー伝導に関するメカニズム研究.
- 運動活動中のタンパク質構成の変化の調査.
主要な成果:
- キネシンとミオシンモーターは,保存されたコア構造を共有しています.
- 両方のモータータイプは,ATPエネルギーを運動に変換するために,形状の変化の類似した戦略を使用します.
- 様々な機械増幅器が保存されたコアと結合され,機能的な専門化につながります.
結論:
- 分子モーターは,保存されたコアと変数メカニカル要素を組み合わせたモジュラーデザインを備えています.
- このモジュラリティは,キネシンとミオシンファミリーで観察された幅広い専門機能を説明します.
- これらの原理を理解することで,細胞の力学とモータータンパク質の進化の洞察が得られます.
関連する概念動画
Mechanical Protein Functions
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
Microtubule Associated Motor Proteins
Eukaryotic cells have different motor proteins for transporting various cargo within the cell. These motor proteins differ based on the filament they associate with, the direction they move within the cell, and the type of cargo they transport. Motor proteins that associate with microtubules are known as microtubule-associated motor proteins. There are two families of microtubule-associated motor proteins —Kinesins and Dyneins. Both these proteins assist in the transport of cellular cargos...
The Movement of Organelles and Vesicles
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,...
Directing Proteins to the Rough Endoplasmic Reticulum
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
Mechanical Protein Function
Proteins perform many mechanical functions in a cell. These proteins can be classified into two general categories- proteins that generate mechanical forces and proteins that are subjected to mechanical forces. Proteins providing mechanical support to the structure of the cell, such as keratin, are subjected to mechanical force, whereas proteins involved in cell movement and transport of molecules across cell membranes, such as an ion pump, are examples of generating mechanical force.
Protein Dynamics in Living Cells
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...


