プログラム可能なDNAオリガミの脚架によって明らかにされた,モータータンパク質の合体における牽引戦
N D Derr1, B S Goodman, R Jungmann
1Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
まとめ
合成DNA オリガミの貨物制御モーター・アンサンブルで,モーター番号を明らかにすることは速度に影響を最小限にするが,反対極性のモーターは解決可能な戦いに巻き込まれる. これは,細胞内輸送の調整に関する理解を深める.
科学分野:
- 細胞生物学 細胞生物学
- バイオフィジックス 生物物理学
- 分子モーターは分子モーターです.
背景:
- サイトプラズマのダイネインとキネシン-1は,細胞内輸送に不可欠な対極性のマイクロチューブルモーターである.
- バイディレクショナルな貨物移動はモーター・アンサンブルから生じますが,正確な空間的および時間的な分類が起こります.
- これらのモーター・アンサンブルを調整するメカニズムは,まだ完全に理解されていない.
研究 の 目的:
- マイクロチューブルベースのモーターのアンサンブルを制御する調整メカニズムを調査する.
- 制御可能な合成貨物システムを開発し,モーターアンサンブルダイナミクスのインビトロ研究を行う.
主な方法:
- 3D DNA オリガミを使ってプログラム可能な合成貨物を製造しました.
- 制御されたタイプ,数,間隔,および方向性を有するDNAオリゴヌクレオチド結合モーター (ダイネインおよびキネシン-1) の異なる数値が付属しています.
- in vitroでモーターアンサンブルの行動を分析した.
主要な成果:
- 同極性モーター (1-7モーター) のアンサンブルでは,モーター数を増やすことが方向速度に最小限の影響を及ぼした.
- 反対極性のモーターのアンサンブルは"引きずる戦争"の行動を示した.
- この引きずる戦いは,一つの運動種を排除することで解決できる.
結論:
- モーター番号は,同一極性組の速度の主な決定因子ではありません.
- 反対極のモーターの相互作用は,貨物輸送の規制にとって決定的な,解決可能な牽引力を生み出します.
- この合成システムは,細胞プロセスにおける複雑な運動協調を解剖するためのプラットフォームを提供します.
関連する概念動画
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...
Assembly of Cytoskeletal Filaments
Cytoskeletal filaments are polymeric forms of smaller protein subunits. However, individual cytoskeletal filaments may easily disassemble or associate with other similar filaments to form rigid structures. Microfilaments, made of actin monomers, rely on actin-binding proteins to form bundles and create networks of individual actin filaments. Microtubules rely on microtubule-associated proteins (MAPs) to form sturdy cylindrical structures. However, the proteins involved in forming complex...
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.
Assembly of Complex Microtubule Structures
Complex microtubule structures are present in resting cells and in dividing cells. In resting cells, they are responsible for maintaining the cellular architecture, tracks for intracellular transport, positioning of organelles, assembly of cilia and flagella. They mediate the bipolar spindle assembly for chromosomal segregation and positioning of the cell division plate in dividing cells. The formation of microtubule complex structures depends on the cell type, cell stage, and cell function.
Single-Strand DNA Binding Proteins
For successful DNA replication, the unwinding of double-stranded DNA must be accompanied by stabilization and protection of the separated single strands of the DNA. This crucial task is performed by single-strand DNA-binding (SSB) proteins. They bind to the DNA in a sequence-independent manner, which means that the nitrogenous bases of the DNA need not be present in a specific order for binding of SSB proteins to it. The binding of SSB proteins straightens single-stranded DNA (ssDNA) and makes...
Generation of Straight or Branched Actin Filaments
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...


