Differential effects of C-terminal mutants on actin polymerization by the FFC construct.
A, pyrene-actin polymerization assays containing 2 μm actin monomers (5% pyrene) with 40 nm concentrations of the indicated FFC constructs. B, filament production at 50% polymerization by the indicated FMNL3 constructs. C, pyrene-actin polymerization assays containing 2 μm actin monomers (5% pyrene) with 40 nm concentrations of the indicated FF constructs. D, quantification of filament lengths in a severing assay using 2 μm polymerized actin and 400 nm concentrations of the indicated FMNL3 construct. E, pyrene-actin polymerization assays containing 2 μm actin monomers (5% pyrene) with 25 nm FFC-WT (red), FFC-3xR (blue), or FFC-WH2/3xR (green). F, competition binding assays using 20 nm FL-Cterm-WT, 1 μm latrunculin B-bound actin monomers, and increasing concentrations of GST-Cterm-WT, GST-Cterm-3xR, or GST-Cterm-WH2/3xR.