2025-12-24 国立遺伝学研究所
(上) 生きている細胞の中でおこる2つの動き。ダイニンという分子モーターが細胞の中で輸送をおこない、その周囲ではミオシンとアクチンという分子がネットワーク (アクトミオシンネットワーク) をつくり、ランダムな動きと力を生み出している。(下) アクトミオシンネットワークが生み出すランダムな動きが強いほどダイニンによる輸送は速くなる。
<関連情報>
- https://www.nig.ac.jp/nig/ja/2025/12/research-highlights_ja/rh20251223-2.html
- https://www.cell.com/iscience/fulltext/S2589-0042(25)02357-0
細胞質アクトミオシンネットワークの活発な変動がダイニン駆動輸送を促進する Active fluctuations of cytoplasmic actomyosin networks facilitate dynein-driven transport
Takayuki Torisawa ∙ Kei Saito ∙ Ken’ya Furuta ∙ Akatsuki Kimura
iScience Published:November 17, 2025
DOI:https://doi.org/10.1016/j.isci.2025.114096
Highlights
- Cytoplasmic environment accelerates dynein-driven transport
- Reducing actomyosin activity decreases the speed of dynein-driven transport
- Increasing actomyosin activity enhances dynein-driven transport
- Rectification of cytoplasmic random forces may contribute to in vivo acceleration
Summary
Inside cells, molecular motors transport cargo through a highly crowded cytoplasmic environment. While such an environment is assumed to hinder transport, its precise effect remains unclear. Here, we investigated how the dynamics of cytoplasmic environments affect dynein-driven transport in C. elegans early embryos. In living embryos, we found that an artificial dynein-cargo complex exhibited significantly faster transport than in vitro, indicating an active acceleration mechanism in vivo. By altering the activity of actomyosin networks, we found that dynein-driven transport was accelerated by actomyosin-driven cytoplasmic fluctuations, with speed increasing upon myosin upregulation and decreasing upon its depletion. Furthermore, in vitro force measurements of dynein suggest that the asymmetric force response to random forces, generated by fluctuating dynamics of actomyosin networks, may contribute to acceleration. This study provides insights into a regulatory mechanism of molecular motors within fluctuating cytoplasm, harnessing cytoplasmic fluctuations to enhance transport efficiency in a highly crowded environment.
