Actin remodeling

Actin remodeling is a biochemical process in cells. In actin remodeling, there is a cycle of actin monomers being polymerized, affecting the cell membrane, and being broken down into monomers again. Actin filament remodeling occurs on cell surfaces, and the variety of actin filament lengths and shapes caused by actin-binding proteins (ABPs) accounts for the diverse structure and changes in shape of eukaryotic cells.

Actin remodeling cycle
Cell surface (cortical) actin remodeling has a nine-step cyclic process, and each step is responsive to cell signaling, making this a dynamic process. Actin starts out as a monomer, is transformed into a polymer with attached ABPs, and is disassembled back into a monomer so the process can start over again.


 * 1. Initiation and barbed-end uncapping


 * 2. Elongation and barbed-end capping


 * 3. Termination
 * Barbed-end capping
 * Polymerization promoters, barbed-end capping inhibitors
 * Lateral stabilization


 * 4. Branching amplification


 * 5. Actin filament crosslinking


 * 6. Actin filament contraction and cargo motoring


 * 7. Membrane attachment


 * 8. Actin filament disassembly
 * Strong filament severing and barbed-end capping
 * Weak severing
 * Accelerated pointed-end depolymerization


 * 9. Monomer sequestration that prevents spontaneous nucleation