FIGURE 12.

FRL2N inhibits actin polymerization induced by FRL2.FH2.2+3 but not by FRL2.FH2. Purified FRL2.FH2 and FRL2.FH2.2+3 derivatives were tested in pyrene-actin polymerization assays at the indicated concentrations in the presence or absence of purified FRL2N. A, FRL2 FH2 (60 nm) induces actin polymerization. This polymerization is not inhibited by preincubation with FRL2N (20, 60, and 180 nm). FRL2N alone (180 nm) has no effect on polymerization. B, FRL2.FH2.2+3 (60 nm) induces actin polymerization and is inhibited by preincubation with FRL2N (20, 60, and 180 nm). C, FRL2N alone (180 nm) does not affect actin polymerization. G-actin concentration was 2 μm. A.U., absorbance unts.