Rate of treadmilling of actin filaments in vitro.
Actin filaments capped at the barbed ends were formed by polymerizing monomeric actin onto a gelsolin-actin complex. The rate of depolymerization and polymerization of the pointed ends was determined by diluting gelsolin-capped actin filaments into various concentrations of monomeric actin. Under the conditions of the experiments (100 mM-KCl, 2 mM-MgCl2 at 37 degrees C) the rate constant of dissociation of subunits both from a shortening and a lengthening filament was found to be 0.21 s-1. As the rate of dissociation of subunits from the slow pointed end determines the rate of treadmilling, it is concluded that actin filaments treadmill with a rate of about 2 micron/h.
D008841:Actin Cytoskeleton / Q000032:analysis*; D000199:Actins; D000818:Animals; D002135:Calcium-Binding Proteins; D003599:Cytoskeleton / Q000032:analysis*; D018260:Gelsolin; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D011817:Rabbits
D000199:Actins; D002135:Calcium-Binding Proteins; D018260:Gelsolin; D046911:Macromolecular Substances; D008840:Microfilament Proteins