Stabilizing the Transcription Factors by E3 Ligase COP1.

Photomorphogenesis is oppositely regulated by two groups of transcription factors. CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) degrades the positive factors but stabilizes the negative ones to predominantly repress photomorphogenesis. It is known that COP1 degrades substrates as an E3 ligase. Two recent studies unraveled the long-sought mechanisms of how COP1 stabilizes the negative transcription factors.