InterPro domain: IPR042755

COP1 is a RING finger-type ubiquitin E3 ligase. In Arabidopsis, it is a central switch for the transition from plant growth underground in darkness (etiolation) to growth under light exposure (photomorphogenesis) [ 1 ]. In mammals, it functions as an E3 ubiquitin-protein ligase involved in tumorigenesis, gluconeogenesis, and lipid metabolism. It is regulated by the COP9 signalosome [ 2 ] and is involved in 14-3-3 delta ubiquitin-mediated degradation [ 3 ]. COP1 contains a classic leucine-rich NES and a novel bipartite NLS bridged by a RING finger domain [ 4 ].

1. Short Hypocotyl in White Light1 Interacts with Elongated Hypocotyl5 (HY5) and Constitutive Photomorphogenic1 (COP1) and Promotes COP1-Mediated Degradation of HY5 during Arabidopsis Seedling Development. Plant Physiol. 169, 2922-34
2. Constitutive photomorphogenesis protein 1 (COP1) and COP9 signalosome, evolutionarily conserved photomorphogenic proteins as possible targets of melatonin. J. Pineal Res. 61, 41-51
3. COP9 signalosome subunit 6 stabilizes COP1, which functions as an E3 ubiquitin ligase for 14-3-3σ. Oncogene 30, 4791-801
4. An initial biochemical and cell biological characterization of the mammalian homologue of a central plant developmental switch, COP1. BMC Cell Biol. 3, 30