FIGURE 5.

The p40/ARPC1 “arm” domain binds to the VCA domain of Las17/WASp. A, 2 μm soluble Arc40 arm was incubated for 10 min with control beads or beads coated with full-length Las17/WASp or its VCA domain. The beads were pelleted, and the percentage of Arc40 arm bound was determined by analyzing pellets and supernatants on Coomassie-stained gels. B, wild type and mutant (arc40-140) GST-Arc40 arm peptides were immobilized on glutathione-agarose beads and incubated with 100 nm soluble, full-length Las17/WASp. The beads were pelleted, and the percentage of Las17/WASp bound was determined by analysis of the supernatant fractions by immunoblotting with anti-VCA antibodies. C, 75 nm wild type ARC40, arc40Δ311–340, or arc40-140 Arp2/3 complex was incubated with GST-VCA coated beads. The beads were pelleted, and the relative amounts of Arp2/3 complex bound were determined by analysis of the pellet fractions by immunoblotting with anti-Arp2 antibodies.