| DACH 1 inhibits transforming growth factor beta signaling through binding Smad 4 . ^^^ DACH 1 bound to endogenous NCoR and Smad 4 in cultured cells and DACH 1 co localized with NCoR in nuclear dotlike structures . ^^^ Smad 4 was required for DACH 1 repression of Smad signaling . ^^^ In Smad 4 null HTB 134 cells , DACH 1 inhibited the activation of SBE 4 reporter activity induced by Smad 2 or Smad 3 only in the presence of Smad 4 . ^^^ The DS domain of DACH was sufficient for NCoR binding at a Smad 4 binding site . ^^^ |