The expression of the FH2 domain of INF2 restores Glu-MT formation and MTOC polarization in Rac1- or Cdc42-KD cells. (A and B) Jurkat cells were transfected with DNA constructs coexpressing GFP and shRhoA, shRac1, or shCdc42, and were immunoblotted for RhoA, Rac1, Cdc42, or GAPDH (A). The histogram represents the percentage of RhoA, Rac1, and Cdc42 content (B). (C and D) RhoA-, Rac1-, or Cdc42-KD cells were left untransfected (C and D) or were transfected with the construct expressing the FH2 domain of INF2 as indicated (D). After conjugation to SEE-loaded APCs, cells were stained for Glu- and Tyr-MTs (C). The histogram represents the percentage of T cells with Glu-MTs or with polarized MTOC (D). (E) Control, Rac1-KD, or Cdc42-KD cells were treated with 3 nM taxol for 18 h. After conjugation to SEE-loaded APCs, cells were stained for Glu- and α-tubulin. The histogram represents the percentage of T cells with Glu-MTs or polarized MTOC (E). The arrowheads indicate the position of the MTOC of the T cells. At least 40 T cells were analyzed in D and E. Data in B, D, and E are summarized as means ± SEM from three independent experiments (error bars; *, P < 0.05; **, P < 0.01; ***, P < 0.001). Bars, 5 µm.