キネシンは,両手を交わして歩いている.
Ahmet Yildiz1, Michio Tomishige, Ronald D Vale
1Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA.
まとめ
キネシン運動タンパク質は,インチワームモデルではなく,ハンド・オーバー・ハンドメカニズムで動く. シングルキネシンヘッドは大きなステップを踏んで,一時停止と交互に,このモデルをサポートします.
科学分野:
- 分子モーター機能は分子モーター機能である.
- 細胞輸送メカニズムは,細胞の輸送メカニズムです.
- タンパク質の移動の生体物理学
背景:
- キネシンは,マイクロチューブルに沿って貨物を運ぶ重要な運動タンパク質です.
- キネシンの正確なステップメカニズム (ハンド・オーバー・ハンド vs. インチワーム) は,長年にわたり議論されてきた.
- キネシンの動きを理解することは,細胞生物学と疾患の研究において極めて重要です.
研究 の 目的:
- キネシンモータータンパク質のステップメカニズムを解明する.
- キネシンの運動性のハンド・オーバー・ハンドとインチワームモデルを区別する.
- 個々のキネシンの頭の動きに関する高解像度データを提供するためです.
主な方法:
- 単分子光顕微鏡を用いて,キネシンヘッドにラベルを貼り,追跡した.
- 精密な局所化のために,単一のキネシンヘッドにCy3フッ素ホルダーが付着しました.
- 高解像度トラッキングにより,各ステップの前後に2nm以内の染料の位置が決定されます.
主要な成果:
- 個々のキネシンヘッドは17.3 ± 3.3 nmのステップをとることが観察されました.
- 運動分析は,これらの大きなステップが0nmステップ (一時停止) と交互に交互に変化することを明らかにしました.
- 観察された段階的なパターンは,ハンド・オーバー・ハンドメカニズムを強く支持しています.
結論:
- この発見は,キネシンの運動性における"手と手"のメカニズムの有力な証拠を提供する.
- この結果は,マイクロチューブルに沿ってキネシンの移動に関するインチワームモデルを否定している.
- キネシンは,ATP結合の一時停止の間,微小管に二重頭部結合を維持している可能性が高い.
関連する概念動画
Crossing Over
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
Social Traps
Social traps are negative situations where people get caught in a direction or relationship that later proves to be unpleasant, with no easy way to back out of or avoid. The concept was orignally introduced by John Platt who applied psychology to Garrett Hardin's "Tragedy of the Commons", where in New England herd owners could let their cattle graze in the common ground. This situation seems like a good idea, but an individual could have an advantage. If they owned more cows, the larger...
Short-distance Transport of Resources
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
Crossing over
Unlike mitosis, meiosis aims for genetic diversity in its creation of haploid gametes. Dividing germ cells first begin this process in prophase I, where each chromosome—replicated in S phase—is now composed of two sister chromatids (identical copies) joined centrally.
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
The homologous pairs of sister chromosomes—one from the maternal and one from the paternal genome—then begin to align alongside each other lengthwise, matching corresponding DNA positions in a process called synapsis.
In order to...
Crossing Over
Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I, duplicated...
Direct Motor Pathways
The direct motor pathways, also known as the pyramidal tracts, are a group of neural pathways that originate in the brain and descend through the spinal cord. They control the voluntary movement of the body. There are two major direct motor pathways: the corticospinal and the corticobulbar tracts.
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and the...


