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.^[1]

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]

• 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

References

1. ^ ^{a b} Thomas P. Stossel, Gabriel Fenteany, and John H. Hartwig (2006). "Cell surface actin remodeling". Journal of Cell Science (The Company of Biologists) 119 (Pt 16): 3261–3264. doi:10.1242/jcs.02994. PMID 16899816. http://www.biochemweb.org/fenteany/publications/pdf/JCellSci2006.pdf. 

See also

• Actin remodeling of neurons

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