Actin remodeling

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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[edit]

Cell surface (cortical) actin remodeling is a 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][2]

  • Initiation: de novo nucleation and barbed-end uncapping
  • Elongation (facilitated in vivo by polymerization promoters and barbed-end capping inhibitory proteins)
  • Termination (barbed-end capping)
  • Branching amplification (nucleation of new filaments from sides of existing filaments)
  • Actin filament crosslinking (lateral stabilization of actin filament network)
  • Actin filament contraction and cargo motoring
  • Membrane attachment through membrane-actin linker proteins
  • Actin filament disassembly
Strong filament severing and barbed-end capping
Weak severing
Accelerated pointed-end depolymerization
  • Monomer sequestration that prevents spontaneous nucleation

See also[edit]

References[edit]

  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. 
  2. ^ Klemens Rottner, Theresia E.B. Stradal (2011). "Actin dynamics and turnover in cell motility." Current Opinion in Cell Biology 23(5):569-578. doi: 10.1016/j.ceb.2011.07.003. PMID 21807492