Figure 1From: Non-degradative ubiquitination in Smad-dependent TGF-β signalingSchematic diagram of ubiquitination sites in Smad3 and Smad4. The conserved MH1 domain and MH2 domain are shown in blue and red, respectively. The non-conserved regions including the linker are shown in white. PY-motif, which is important for Smurf2 binding and ubiquitination, is shown in green.Back to article page