Figure 2From: An initial biochemical and cell biological characterization of the mammalian homologue of a central plant developmental switch, COP1Association of mammalian COP1 with ubiquitin and ubiquitinated protein in vivo. (A) Mammalian COP1 associates to ubiquitinated proteins in vivo. Lysates from 293 cells transfected with FLAG-tagged MmCOP1 and/or HA-tagged ubiquitin were subjected to immunoprecipitation by an anti-FLAG antibody, followed by immunoblotting by anti-HA and anti-FLAG antibodies as indicated. Molecular weights (in kDa) and IgG band are indicated on the left. IP, immunoprecipitation; IB, immunoblot. (B) Mammalian COP1 is a ubiquitination substrate. FLAG-tagged MmCOP1 or N280 and His-tagged ubiquitin were either co-transfected or individually transfected into 293 cells as indicated. His-tagged ubiquitinated protein was purified from the cell lysates under denaturing condition (in 8 M urea) by using Ni-NTA agarose beads. Immunoblot was performed by using an anti-FLAG antibody as indicated.Back to article page