TTRAP
Transforming growth factor-β principally relays its effects through the Smad pathway however, accumulating evidence indicate that alternative signalling routes are also employed by this pleiotropic cytokine. For instance recently, we have demonstrated that ligand-occupied TGF-β receptors can directly trigger the TRAF6-TAK1 signalling module, resulting in MAP kinase activation. Here we report identification of the adaptor molecule TTRAP as a novel component of this non-canonical TGF-β pathway. We show that the protein associates with TGF-β receptors and components of the TRAF6-TAK1 signaling module, resulting in differential regulation of TGF-β activated p38 and NF-κB responses. Modulation of cellular TTRAP level affects cell viability in the presence of TGF-β, suggesting that the protein is an important component of the TGF-β induced apoptotic process.