FIGURE 6.

The first α-helix of POP2 is functionally sufficient to regulate TNFα response to LPS and F. novicida infection. A, flow cytometry analysis showing intracellular staining against the indicated stable transfectants in J774A.1 cells. The plots described in the legend for Fig. 2A and this panel are from the same experiment but are shown separately for clarity. B and C, J774A.1 cells stably expressing pcDNA3, POP2 WT, or the indicated POP2 mutants were treated with LPS for 18 h (B) or infected with F. novicida for 24 h (C) followed by TNFα measurement in culture supernatant. A representative experiment is shown of least three experiments showing similar results (error bars, S.D.). Statistics were performed using two-tailed Student's t test (*, p < 0.05; **, p < 0.001).