ロケットランチャーメカニズムは,単一分子イメージングによって定義された共同アクチンアセンブリの共同アクチンアセンブリです
Dennis Breitsprecher1, Richa Jaiswal, Jeffrey P Bombardier
1Department of Biology, Brandeis University, Waltham, MA 02454, USA.
まとめ
Adenomatous polyposis coli (APC) とmDia1のタンパク質複合体は,アクチンフィラメントの組み立てを開始する. これらの要素は分離し,mDia1がフィラメントの成長を追跡し,APCは核形成部位に残ります.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- バイオケミストリー バイオケミストリー
背景:
- アクチン組成は,細胞機能にとって極めて重要です.
- APCやmDia1のような相互作用する因子のアクチン核形成と伸縮における正確な役割は不明である.
研究 の 目的:
- アデノマトス・ポリポシス・コライ (APC) とmDia1が協力してアクチンフィラメントの組み立てを開始するメカニズムを解明する.
- アクチンポリメリゼーション中のAPCとmDia1のダイナミックな行動を調査する.
主な方法:
- 三色単分子光顕微鏡を用いた.
- フィラメント形成中のAPC,mDia1,アクチンモノマーの空間と時間のダイナミクスを視覚化しました.
主要な成果:
- APC,mDia1,およびアクチン単体複合体がアクチンフィラメント形成を開始することが観察されました.
- これらの複合体は,タンパク質とプロフィリンを制限することで,抑制をうまく克服しました.
- ポリメリゼーションの後,APCとmDia1は解離し,mDia1は成長するフィラメントの刺さった端に沿ってプロセス的に移動し,APCは核形成部位に残ります.
結論:
- APCとmDia1は直接相互作用し,アクチンフィラメントの組み立てを開始する.
- これらの因子は核形成後に分離し,線維の延長と安定化に異なる役割を果たします.
さらに関連する動画
関連する概念動画
Formation of Higher-order Actin Filaments
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin networks...
The high-order actin networks...
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...
Mechanism 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...
Actin Polymerization
Actin polymerization occurs through the head-to-tail association of binding sites on monomeric actin or G-actin to form filamentous or F-actin. The polymerization can be divided into three phases ̶ nucleation, elongation, and steady-state phase.
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight actin...
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight actin...
Actin Filament Depolymerization
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...
Mechanism 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...


