B-box type zinc finger protein with CCT domain-containing protein;(source:Araport11)
TAIR Curator Summary:
Acts as a positive regulator of red light signaling; overexpression causes markedly shortened hypocotyls under various light states. Binds to the HY5 promoter to activate its transcription, while both BBX21 and HY5 associate with its promoter to positively regulate its expression. T