Erythrocyte protein and phosphorylation profile in Rac1^–/–;Rac2^–/– RBCs evaluated in SDS-polyacrylamide gels. (A) RBC ghost electrophoretic pattern in Rac1^–/–;Rac2^–/– versus WT erythrocytes. Molecular weight markers and major RBC cytoskeleton proteins are indicated. Densitometry scans of the 2 lanes, respectively, are shown on the right with spectrin and actin bands noted between the dotted lines. The actin-to-spectrin ratio was reproducibly 2 to 3 times higher in the Rac1^–/–;Rac2^–/– ghosts versus the WT ghosts. (B) Profile of the major actin-interacting proteins and serine phosphorylation of adducin in WT and Rac1^–/–;Rac2^–/– erythrocytes (2 μL packed RBCs loaded/lane). Two different samples from each genotype are shown. (C) Triton-soluble (S) and pellet (P) fractions of erythrocyte ghosts evaluated by immunoblotting for the presence of spectrin, adducin, actin, and phospho-adducin (Ser724). All images are representative of at least 6 different blood samples from each genotype.