Actin filament (F-actin)

An actin filament (F-actin) is a helical polymer composed of polymerized globular actin (G-actin) subunits that forms a major component of the eukaryotic cytoskeleton[1][3][5]. These filaments are highly dynamic and polar, with distinguishable "barbed" (plus) and "pointed" (minus) ends, and are essential for providing structural support, cell movement, cytokinesis, and, in muscle, facilitating contraction through interactions with myosin[1][3][4][5][9]. Actin filaments can assemble into various higher-order structures in association with numerous actin-binding proteins, and their regulated polymerization and depolymerization are critical for a range of cellular processes including cell shape modulation, intracellular transport, and cellular signaling[1][7][9]. In muscle tissue, actin filaments are known as "thin filaments," which slide against myosin to produce contraction[5][9]. Actin filament dysregulation or mutation is implicated in diseases such as cancer, cardiovascular disorders, some neurodegenerative syndromes, and infection[9]. Certain small molecules and toxins can bind F-actin to either inhibit its polymerization or stabilize filaments, some of which are tools in research or proposed as drug leads, but no clinically approved drugs selectively target actin filaments due to the high risk of severe systemic toxicity[2][3][4].

Other names

Filamentous actinF-actinMicrofilamentActin microfilamentThin filament

Actin polymerization inhibition, Actin filament stabilization, Actin filament depolymerization