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Published on: July 30, 2014
[Structure, function and modulation of actin-related protein 2/3 complex].
1Department of Pathophysiology of the First Military Medical University.
Sheng Li Ke Xue Jin Zhan [Progress in Physiology]
|February 25, 2005
Summary
The Actin-related protein 2/3 (Arp2/3) complex is crucial for forming microfilaments, essential for cell shape and migration. Understanding its structure and function aids in comprehending cytoskeleton dynamics and signaling.
Area of Science:
- Cell Biology
- Biochemistry
- Biophysics
Context:
- Microfilaments, polymers of actin, are fundamental cytoskeletal components.
- The Actin-related protein 2/3 (Arp2/3) complex is a key regulator of actin nucleation.
- Cellular processes like migration and shape maintenance depend on dynamic microfilament networks.
Purpose:
- To elucidate the structure, function, and modulation of the Arp2/3 complex.
- To understand the mechanisms governing microfilament formation.
- To explore the interplay between the cytoskeleton and signaling pathways.
Summary:
- The Arp2/3 complex, comprising seven subunits, is modulated by nucleation promoting factors (NPFs).
- It plays a critical role in initiating new actin filaments, influencing cellular architecture and motility.
- Research into the Arp2/3 complex provides insights into fundamental cellular processes.
Impact:
- Enhances understanding of cytoskeletal dynamics and cell motility.
- Provides a basis for investigating diseases linked to cytoskeletal dysfunction.
- Informs the development of targeted therapies affecting actin dynamics.
Related Concept Videos
01:18Assembly 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...
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.
01:42Actin 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...
01:14Generation 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...
01:11Formation 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...
01:13Actin Polymerization and Cell Motility
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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.