The F-box protein FKF1 inhibits dimerization of COP1 in the control of photoperiodic flowering

摘要: In Arabidopsis thaliana, CONSTANS (CO) plays an essential role in the regulation of photoperiodic flowering under long-day conditions. CO protein is stable only afternoon long days, when it induces expression FLOWERING LOCUS T (FT), which promotes flowering. The blue-light photoreceptor FLAVIN-BINDING, KELCH REPEAT, F-BOX1 (FKF1) interacts with and stabilizes by unknown mechanism. Here, we provide genetic biochemical evidence that FKF1 inhibits CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1)-dependent degradation. Light-activated has no apparent effect on COP1 stability but can interact negatively regulate COP1. We show inhibit homo-dimerization. Mutation coiled-coil domain COP1, prevents dimer formation, impairs function coordinating time. Based these results, propose a model whereby light- day length-dependent interaction between controls to conditions rapidly degraded short-day Here authors E3 ligase light-dependent manner prevent degradation