Fig. 5. Interaction between CARD4 and RICK and RICK and IKKα of the IKK complex folowing S. flexneri infection. (A) Immunoprecipitation using anti-RICK antibodies demonstrates that RICK and CARD4 interact transiently following S. flexneri infection. (B) Immunoprecipitation of the IKK complex using anti-IKKα antibodies showed that RICK (both endogenous and overexpressed vsv-tagged forms of RICK) associates transiently with the IKK complex following S. flexneri infection. Experiments were carried out using HEK293 cells as in Figure 3.