Subcellular localization of bbx24COP1, and colocalization analysis of BBX24 variants and COP1 by transient expression. Arabidopsis protoplasts were transfected with EGFP-bbx24COP1 (A), or cotransfected with BBX24 wild-type or mutant proteins (B–E), and COP1 fused to ECFP and EYFP, respectively. Representative images of the fluorescence signals detected by CLSM of cells coexpressing ECFP-BBX24 and EYFP-COP1 (nuclear or cytosolic colocalization are indicated with a white or a yellow arrow, respectively; B); ECFP-bbx24NLS and EYFP-COP1 (C); ECFP-N-BBX24 and EYFP-COP1 (D); and ECFP-bbx24COP1 and EYFP-COP1 (E). Bar = 10 μm.