Role of adapter function in oncoprotein-mediated activation of NF-κB -: Human T-cell leukemia virus type i tax interacts directly with IκB kinase γ

Mechanisms by which the human T-cell leukemia virus tyre I Tax oncoprotein activates NF-kappa B remain incompletely understood. Although others have described an interaction between Tax and a holo-I kappa B kinase (IKK) complex, the exact details of protein-protein contact are not fully defined. Here we show that Tax binds to neither IKK-alpha nor IKH-beta but instead complexes directly with IKK-gamma, a newly characterized component of the IKK complex. This direct interaction with IKK-gamma correlates with Tax-induced I kappa B-alpha phosphorylation and NF-kappa B activation, Thus, our findings establish IKK-gamma as a key molecule for adapting an oncoprotein-specific signaling to IKK-alpha and IKK-beta.