関連する実験動画
Updated: Jul 7, 2026
08:57
Aip1p Dynamics Are Altered by the R256H Mutation in Actin
Published on: July 30, 2014
アクチンベースの運動性のメカニズム
D Pantaloni1, C Le Clainche, M F Carlier
1Dynamique du Cytosquelette, Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
Science (New York, N.Y.)
|May 31, 2001
まとめ
細胞の運動性と突起は,アクチンポリメリゼーションによって引き起こされます. 研究者は,このプロセスを5つのタンパク質を使用してインビトロで再構成し,重要なメカニズムとして規制されたアクチンフィラメントトレッドミリングを明らかにしました.
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
背景:
- 空間的に制御されたアクチンポリメリゼーションは,細胞の運動性と,ラメリポディアのような細胞突起の形成を促します.
- Listeria monocytogenes や Shigella flexneri のような病原体は,アクチンベースの推進力を利用し,ラメリポディアのダイナミクスモデルとして機能しています.
研究 の 目的:
- アクチンベースの運動性のための最低限のタンパク質の要件を復元し,分析する in vitro.
- 簡素化されたシステムを使用して,アクチンベースの推進の基礎となるメカニズムを解明する.
主な方法:
- 5つの精製されたタンパク質を用いたアクチンベースの運動性の再構成.
- アクチン・フィラメントの動態と細菌や微小球の動きの観察と分析 in vitro.
主要な成果:
- アクチンベースの運動性は,わずか5つの純粋なタンパク質を使用して,試験管内で成功裏に再構成されました.
- 再構成されたシステムは,アクチンフィラメントの規制された,サイト指向のトレッドミリングを実証しました.
- 観察されたアクチンダイナミクスは,生きている運動細胞と,合成媒体の構成要素の性質と一致しています.
結論:
- アクチンベースの運動性を駆動するには,最小限の5つのタンパク質が十分です.
- 規制されたアクチンフィラメントのトレッドミリングは,アクチンベースの推進のための基本的なメカニズムです.
- この in vitro システムは,細胞の運動性と病原菌の侵入を研究するための強力なモデルを提供します.
関連する概念動画
01:26Introduction to Actin
Actin is a highly conserved cytoskeletal protein found abundantly in eukaryotic cells. It constitutes 10% weight of the total cellular protein in muscle cells, while in non-muscle cells, it is lower and makes up around 1–5 percent of the total cell protein. Actin found in the unicellular amoebae and complex multicellular animals is around 80% similar, demonstrating their conservation over a billion years of evolution. Actin coding genes are conserved within species and across different species.
01:13Actin Polymerization and Cell Motility
Actin is a family of globular proteins that are highly abundant in eukaryotic cells. It makes up approximately 1-5% of total cell protein concentration. Actin monomers polymerize to form a complex network of polarized filaments, the actin cytoskeleton, that plays a crucial role in many cellular processes, including cell motility, division, endocytosis, and metastasis of cancer cells.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:31Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
01:18Role of Myosin in Cell Migration
Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Myosin II is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
01:18Actin Treadmilling
Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...