RESUMO
Systematic control of the transforming growth factor-ß (TGFß) pathway is essential to keep the amplitude and the intensity of downstream signalling at appropriate levels. Ubiquitination plays a crucial role in the general regulation of this pathway. Here we identify the deubiquitinating enzyme OTUD4 as a transcriptional target of the TGFß pathway that functions through a positive feedback loop to enhance overall TGFß activity. Interestingly we demonstrate that OTUD4 functions through both catalytically dependent and independent mechanisms to regulate TGFß activity. Specifically, we find that OTUD4 enhances TGFß signalling by promoting the membrane presence of TGFß receptor I. Furthermore, we demonstrate that OTUD4 inactivates the TGFß negative regulator SMURF2 suggesting that OTUD4 regulates multiple nodes of the TGFß pathway to enhance TGFß activity.
