182515  Arp2/3 Complex Inhibitor I, CK-666

2-Fluoro-N-(2-(2-Methyl-1H-indol-3-yl)ethyl)benzamide, CK-0944666, Actin Assembly Inhibitor XIII

A cell-permeable indolyl-fluorobenzamide compound that selectively inhibits actin assembly mediated by actin-related protein Arp2/3 complex of human, bovine, fission yeast S. pombe, and budding yeast S. cerevisiae origin (IC₅₀ = 4, 17, 5, and 12 µM, respectively), without affecting S. pombe formin domain Cdc12(FH2)-mediated or the spontaneous actin polymerization. Shown to inhibit the actin filament "comet tails" formation around intracellular Listeria in infected SKOV3 cells (IC₅₀ = 7 µM) in a reversible manner. Structrual studies indicate that CK-666 targets a pocket formed between subdomain 4 of Arp2 and subdomain 1 of Arp3, preventing Arp2/3 from shifting into an active conformation upon N-WASP-VCA binding. CK-666 and CK-869 (Cat. No. 182516) exhibit different modes of binding, resulting in their different yeast cross-reactivities. CK-689 (Cat. No. 182517) can serve as a negative control.