DOCK2-mediated Rac activation is critical for IKK-α activation in pDCs. (A) Subcellular localization of IRF-7 was compared between WT and Dock2^−/− pDCs after stimulation with CpG-A. DAPI was used to stain nuclei. Representative images of three independent experiments are shown. Bar, 5 µm. (B) BM-derived pDCs from WT and Dock2^−/− mice were stimulated with 3 µM CpG-A for the indicated times and analyzed for phosphorylation of Akt, ERK, JNK, or p38. Data are representative of at least two independent experiments. (C and D) BM-derived WT and Dock2^−/− pDCs were stimulated with 3 µM CpG-A for the indicated times and analyzed for the expression (C) and autophosphorylation (D) of IRAK-1. Data are representative of two independent experiments. (E–G) BM-derived pDCs from WT, Dock2^−/−, and Tlr9^−/− mice were stimulated with 3 µM CpG-A for the indicated times and analyzed for serine phosphorylation of IKK-α at positions 176 and 180. (G) Before stimulation, cells were treated with bacterially expressed GFP-tagged Tat–T17N-Rac or Tat–WT Rac (500 nM each) for 30 min at 37°C. Data are representative of three (E and G) or two (F) independent experiments.