. "Different types of cell behavior, including growth, motility, and navigation, require actin proteins to assemble into filaments. Here, we describe a biochemical process that was able to disassemble actin filaments and limit their reassembly. Actin was a specific substrate of the multidomain oxidation-reduction enzyme, Mical, a poorly understood actin disassembly factor that directly responds to Semaphorin/Plexin extracellular repulsive cues. Actin filament subunits were directly modified by Mical on their conserved pointed-end, which is critical for filament assembly. Mical posttranslationally oxidized the methionine 44 residue within the D-loop of actin, simultaneously severing filaments and decreasing polymerization. This mechanism underlying actin cytoskeletal collapse may have broad physiological and pathological ramifications." . . "Science" . "Terman J.R." . "Hung R.J." . "Pak C.W." . "2011"^^ . "1710-1713" . "Direct redox regulation of F-actin assembly and disassembly by Mical." . "334" . "doi:10.1126/science.1211956" .