The role of COP1 in repression of Arabidopsis photomorphogenic development

Photomorphogenic development in Arabidopsis is regulated by the key repress or COP1, which interacts with specific transcription factors in the nucleus to modulate their activities. In the dark, COP1 accumulates in the nucleus and represses photomorphogenic development. Light diminishes the nuclear a ccumulation of COP1 and abrogates its repressor activity. A number of cellu lar components are involved in light-dependent nucleocytoplasmic partitioni ng of COP1, including the multisubunit COP9 complexes and at least three we ll-characterized photoreceptors. This review discusses current understandin g of the mechanisms of COP1 action.