How does Arp2/3-mediate the nucleation of branched filaments? The Arp2/3 complex is composed of 7 evolutionarily conserved subunits (Arp2, Arp3, ARPC1-C5) that are structurally similar to the barbed end of actin [1]. The complex [...]

What is actin nucleation? The first step in actin polymerization is known as ‘nucleation’. This step sees the formation of an actin nucleus, which is essentially a complex of three actin monomers, from which [...]

What is the role of formin in actin polymerization? Formins promote the elongation of pre-existing filaments by removing barbed end capping proteins and forming a sleeve around the actin subunits. Formins are also capable [...]

What is the role of cortactin in actin polymerization? Cortactin is a class II nucleation promoting factor (NPF) that binds to actin filaments and influences their stability. Cortactin specifically stabilizes Arp2/3-mediated branch points along [...]

What factors regulate actin filament polymerization? Nucleation Promoting Factors (NPFs) (e.g. WASP, Scar/WAVE) modulate actin filament nucleation by bringing together actin monomers and pre-existing actin filaments, for example, during filopodial initiation where they recruit [...]

What is the steady state phase of actin polymerization? In the steady state phase, the filament dynamics enter a state of equilibrium where monomer disassembly from the (-) end and polymerization at the (+) [...]