Abstract
AtC401 is an Arabidopsis homolog of PnC401 which relates to photoperiodic induction of flowering in Pharbitis nil. C401 genes encode proteins containing a highly conserved pentatricopeptide repeat (PPR) domain. We previously reported that AtC401 expression was regulated by the circadian oscillator. The promoter analysis using the firefly luciferase reporter indicated that the 5’UTR sequence of AtC401 relates to the circadian regulation. To analyze the regulation mechanism in detail, we performed the promoter analysis using an Arabidopsis cultured cells. These analyses revealed that the 86-nt fragment containg 73-nt of 5’UTR is sufficient for the circadian regulation. Because there is no TATA box in the fragment, we suggested that AtC401 requires no TATA box for the transcription. The fragment contains an initiator consensus (Inr) and the tandem repeat of the GAKAA (K=A/T). Therefore, we propose that the Inr and the GAKAA repeat are required for the transcription and the circadian regulation, respectively.
