FIGURE 6.

Site-directed mutagenesis of CP and CAH3a/b. Pyrene-actin polymerization assays were performed as in Fig. 1. The concentrations of CP and CAH3a/b are indicated for each experiment. Two CP mutants were tested for their responsiveness to CAH3a/b (A and B). CAH3a/b mutants were tested for their ability to rescue actin polymerization (C–F). CAH3a/b (A–C) corresponds to residues Ser⁹⁶⁴–Val¹⁰³⁸ of mCARMIL-1, CAH3a (D) corresponds to residues Ser⁹⁶⁴–Gln¹⁰¹⁹, CAH3a*b (E) contains the R993E mutation, and CAH3ab* (F) contains Val¹⁰²⁶, Val¹⁰³⁰, Phe¹⁰³³, and Phe¹⁰³⁴ mutations. a.u., absorbance units.