TRAF2 And NCK Interacting Protein Kinase (TNIK)

TNIK was autophosphorylated in a manner dependent upon lys54 in the ATP-binding pocket of its kinase domain. Immunoprecipitation analysis showed that epitope-tagged TNIK coprecipitated endogenous TRAF2 from human embryonic kidney cells. Mutation analysis revealed that the intermediate domain was sufficient for the interaction, although the GCK domain may contribute.The intermediate domain was also sufficient for interaction with NCK. Cotransfection of TNIK with JNK2 (MAPK9) enhanced JNK2 kinase activity in a dose-dependent manner, and this effect was mediated by the GCK region of TNIK, but not the kinase domain. TNIK overexpression had no effect on ERK1 (MAPK3), p38 (MAPK14), or NF-kappa-B.