The interaction of FAM49B and Rac. The interaction of FAM49B and Rac. (A) Docking of FAM49B with Rac1 was performed by the HADDOCK web server, key residues in FAM49B contributing in the interaction were highlighted in green. (B) FACS analysis of CD69 level upon anti-TCR stimulation in J.FAM49B expressing indicated FAM49 variants. (C) To perform the GST pull-down assay, WT FAM49B or FAM49B (R161D) protein was incubated with GST-Rac or GST-Rac (G12V) protein in vitro in the presence of GST beads. The elutates from the GST beads and input samples were then analyzed by Western blot. Wanjing Shang et al. PNAS 2018;115:17:E4051-E4060 ©2018 by National Academy of Sciences