Interaction between IKKβ and the GMCSF receptor in the yeast 2-hybrid system. (A) Schematic drawing of the IKKβ protein: the part that was used as bait in the yeast 2-hybrid screening is indicated as well as leucine zipper (LZ) and helix-loop-helix (HLH) motifs. (B) Interaction between the cytoplasmic domains of GMRα or GMRβ and IKKβ in the yeast 2-hybrid system. Control transformations contained GMRα or GMRβ combined with empty Gal4-binding domain vector (Gal4BD) lacking IKKβ.