Figure 7. The BL-Induced BIN2 Degradation is an Important Regulatory Mechanism for BIN2 Regulation.
gBIN2:GFP transgenic seedlings were grown on BRZ-containing medium for 2 weeks and transferred to liquid medium containing 100 mM LiCl, 1 μM BL or 1 μM BL plus 10 μM MG132. After immunoprecipitation, BIN2:GFP was used as the kinase for an in vitro phosphorylation assay with GST:BZR1. The amount of immunoprecipitated BIN2:GFP proteins was examined by Western blotting with the monoclonal GFP antibody (top panel). Longer exposure of the blot revealed a ladder of weak bands (indicated by three arrows in the second panel). The phosphorylation levels of GST:BZR1 were visualized by autoradiography (the third panel), and the amounts of the substrate used in the assay were shown by Coomassie Blue staining (bottom panel).