CK-636 is a small molecule inhibitor targeting the Arp2/3 protein complex which regulates actin nucleation and polymerization Specifically CK-636 binds between Arp2 and Arp3 subunits preventing them from adopting the active conformation needed for initiating filamentous actin assembly In biochemical assays CK-636 inhibited Arp2/3-mediated actin polymerization induced by human bovine and fission yeast Arp2/3 complexes with reported IC50 values of 4 M 32 M and 24 M respectively Additionally CK-636 suppressed Arp2/3-dependent actin filament formation in live SKOV3 cells infected with Listeria bacteria exhibiting a concentration-dependent effect (IC50 approximately 22 M) This compound serves as a research tool for studying molecular mechanisms and biological functions involving Arp2/3-mediated cytoskeletal remodeling particularly in the context of cell adhesion junctional integrity and epithelial differentiation