Fig 1.

Activation-induced BCL10 degradation in DT40 B cells requires PKCβ, CARMA1, and TAK1 but not IKKβ. (A) WT, PKCβ, CARMA1^−/−, TAK1^−/−, and IKKβ^−/− DT40 cells were stimulated with P/I for 0 to 2 h. (B) BCL10 densitometry; graphs show the means ± standard errors of the mean (SEM) from six independent experiments. **, P < 0.01 using Student's unpaired t test compared to the same time points in WT and IKKβ^−/− DT40 cells. (C) CARMA1^−/− DT40 cells stably reconstituted with myc-CARMA1-ΔPRD were transfected with empty vector or Flag-IKKβ-DA for 48 h and incubated with CHX for 0 to 7 h. (D) CARMA1^−/− and TAK1^−/− DT40 cells stably reconstituted with myc-CARMA1-WT or myc-CARMA1-ΔPRD were stimulated with P/I for 0 to 120 min (left) or incubated with CHX (right) for 0 to 5 h. (E) WT, CARMA1^−/−, or TAK1^−/− DT40 cells were stimulated with anti-IgM plus an anti-mouse IgM (2nd) or with 2nd only as a control for 0 to 2 h. (F) Jurkat T cells transduced with TAK1 or control shRNAs were stimulated with CD3/CD28 or P/I for 0 to 3 h. (G) Human Ramos B cells stably reconstituted with myc-CARMA1 or myc-CARMA1-ΔPRD were incubated with CHX for 0 to 3 h. In each experiment, whole-cell lysates (WCLs) were immunoblotted with the indicated antibodies (left labels). The signal intensities of BCL10, myc-CARMA1, and pERK (E) are shown in a graph (B) or below the blots (A and C to G) and are calculated as described in Materials and Methods.