Mechanism of action of cytochalasin: evidence that it binds to actin filament ends.
To test the idea that cytochalasin retards actin assembly by binding to filament ends, we have designed a new assay for cytochalasin binding in which the number of filament ends can be varied independently of the total actin concentration. Actin is reacted with polylysine-coated polystyrene beads to make filament ends (Brown and Spudich, 1979, J. Cell Biol. 80:499-504) and then reacted with [3H]cytochalasin B. We have found that cytochalasin B binds to beads in the presence of actin, and that the number of cytochalasin B binding sites can be varied as a function of the number of filament ends independent of the total actin concentration by varying the bead concentration.
D000199:Actins / Q000378:metabolism*; D001665:Binding Sites; D055598:Chemical Phenomena; D002621:Chemistry; D003571:Cytochalasin B / Q000378:metabolism*; D046911:Macromolecular Substances
D000199:Actins; D046911:Macromolecular Substances; D003571:Cytochalasin B