We next sought to determine whether DHX29 physically interacts with RNA sensors or adaptor molecules involved in the type I IFN signaling pathway. Accordingly, co-immunoprecipitation (CO-IP) assays were performed using 293T cells transfected with HA-DHX29 and Flag-RIG-I, Flag-MAVS, or Flag-MDA5. Both human and mouse DHX29 interacted with MDA5, but not with RIG-I or MAVS (Fig 5A and S5A Fig). After demonstrating the specific interaction between DXH29 and MDA5, we investigated the effect of increasing amount of DHX29 expressing vector on the activation of MDA5.