New perspective on the stabilization and degradation of the F-box protein COI1 in Arabidopsis.

The F-box protein CORONATINE INSENSITIVE1 (COI1) assembles into SCF(COI1) complexes and recruits its substrate JAZ proteins for ubiquitination and degradation to regulate diverse aspects of jasmonate-regulated plant developmental processes and defense responses. However, the dynamically regulation of COI1 protein abundance in plants remains unknown. In our Plant Cell paper, through genetic, biochemical analysis and in vitro degradation assays, we demonstrated that the COI1 protein is strictly regulated by a dynamic balance of SCF(COI1)-mediated stabilization and 26S proteasome-mediated degradation, and maintained at a proper level suitable for essential biological processes in plants. In this addendum, we provided additional insights and speculation on the stabilization and degradation of COI1.