It is called a nucleation core because it leads to the energetically favorable elongation reaction once a tetramer is formed from a trimer.
Many distinct proteins that can mediate the de novo nucleation of filaments directly interact with actin and promote it.
[2] The filament becomes less stable as a result of spontaneous ATP hydrolysis and phosphate dissociation, making it more vulnerable to the effects of severing proteins such those in the actin depolymerizing factor (ADF)/cofilin family.
[3] In response to LPS sensing, Arp2/3 significantly reduces actin nucleation at the front, which allows mature DCs to adopt a quick and directional migratory mode.
In contrast to protrusion-based locomotion, the Arp2/3-dependent pool of F-actin present at the front of iDCs limits their migration.