Cdc42/WASp axis regulates CD11b, microtubule association to rafts microdomains. Neutrophils were unstimulated or stimulated with fMLP and plated on Fg-coated slides or on CD11b-coated plates, as indicated in each panels. Western blots of cytosolic and DRM fractions were probed for WASp, CD11b, tubulin, EB-1, actin, Arp-2, or Rho A proteins as indicated in panels A, C, and D Cdc42^−/−, (B-E) WASp^−/−, (F) ITGAM^−/− (CD11b^−/−) cells with their respective WT controls, (G) DRM fraction of WT cells treated with nocodazole. Blots are representative of 3 to 5 independent experiments. (H) Model of long range control of uropod function by Cdc42 in neutrophil polarity: Cdc42 controls WASp activation at the uropod, which induces CD11b clustering and activation; in turn, CD11b recruits EB1 to capture microtubules and activate uropod function.