Figure 5.

(A) Chemoattractant-stimulated alterations in actin polymerization. Wild-type (□), gβ⁻ (░⃞), SN1 (▵), SN2 (▴), SN3 (•), SN4 (▪), and SN5 (○) cells were developed in shaken suspension and then washed in DB buffer, resuspended at 2 × 10⁷ cells/ml. At time zero, 10 nM cAMP was added, and the amount of F-actin at different times was measured and expressed relative to the amount at time zero. Means of an assay performed in duplicate are shown. Independent experiments were done and yielded similar results. (B) Chemotaxis to cAMP. The cells were allowed to develop in suspension for 5 h and then were subjected to the transwell chemotaxis assay to cAMP at concentrations of 0 mM (black bars), 0.1 mM (open bars), 1 mM (light shaded bars), and 10 mM (heavy shaded bars). The number of cells that migrated toward cAMP is indicated. Means and SEMs of at least three duplicates are shown. Two independent experiments were done and yielded similar results.