Actin polymerization

Actin polymerization is a rapid, ATP-dependent cellular process by which actin monomers (G-actin) assemble into polar, double-helical filaments (F-actin), which underpin the cytoskeleton and drive essential functions such as cell movement, shape change, division, and intracellular transport[2][3]. Nucleation is rate-limiting but overcome in vivo by actin-nucleating factors (e.g., Arp2/3 complex for branching, formins for linear extension). Polymerization is tightly regulated by actin-binding proteins such as profilin (assists ATP-actin addition), cofilin (promotes ADP-actin removal and filament severing), gelsolin (severs filaments and caps ends), and thymosin β4 (sequesters actin monomers)[1][2][3][4]. Drugs and toxins can disrupt or stabilize actin polymerization, affecting cellular functions, which is exploited in research and sometimes targeted in disease, though systemic modulation carries high toxicity risks. Actin polymerization dysfunction plays roles in cancer, neurodegeneration, cardiovascular and infectious diseases[2][3][4].

Other names

F-actin formationactin filament assemblyactin network formationactin treadmilling

Inhibition of actin filament assembly (cytochalasin D, latrunculin); Stabilization of actin filaments (phalloidin, jasplakinolide); Modulation of actin-binding protein activity (formins, Arp2/3 complex, cofilin)