The transcription co-repressor TLE1 interacted with the intracellular region of gpl30 through its Q domain.

As the common signal transducer for IL-6 family cytokines, gp 130 interacts with various signal molecules. Our previous work found the amino-terminal enhancer of split (AES) molecule interacts with gp130 intracellular region through its conserved glutamine-rich (Q) domain. The Q domain in AES shares high homology with those in the transcription co-repressor transducin-like enhancer of split (TLE) proteins. The yeast two-hybrid assay, gluthione S-transferase fusion protein pull-down assay and immuno-co-precipitation assay indicated that the Q domain of TLE1 is capable of binding gp130 intracellular domain, and the intracellular membrane proximal region of gp 130 containing conserved Box1 and Box2 motifs seemed essential for this interaction. The interaction between gp130 and TLE1 indicated that molecules of TLE family might play a role in gp 130 signaling.