SMURF1 is an E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and directly transfers the ubiquitin to targeted substrates. SMURF1 interacts with receptor-regulated SMADs specific for the BMP pathway, SMAD1 and SMAD5, in order to trigger their ubiquitination and degradation.The synthetic peptide used to raise the antibody Cat. No. 200125 is selected from a sequence within the center region of human SMURF1. For blocking experiments, a 10 to 100 fold molar excess to antibody is recommended.