Dear Editor,The Arabidopsis CONSTITUTIVELY PHOTOMORPHOGENIC1/ SUPPRESSOR OF PHYA-105 (COP1/SPA) complex is a key repressor of light signaling that inhibits light responses in darkness.It acts as an E3 ubiquitin ligase,which ubiquitinates positively acting light-signaling intermediates,mainly transcription factors,thereby targeting them for proteolytic degradation by the 26S proteasome.In the light,photoreceptors directly interact with the COP1/SPA complex,leading to its inactivation,which subsequently allows the target transcription factors to accumulate and initiate vast reprogramming of gene expression (Huang et al.,2014).