CLOCK/BMAL1 regulates human nocturnin transcription through binding to the E-box of nocturnin promoter.
Nocturnin has been identified as a clock-controlled gene based on its rhythmic expression and night-time peak of transcript level in Xenopus retina. Further studies show that the widespread expression and rhythmicity of nocturnin mRNA level parallel the expression of clock genes. In Xenopus, nocturnin transcription is regulated by cAMP response element-binding protein (CREB) binding the nocturnin element (NE). However, mechanism(s) underlying the regulation of nocturnin transcription in human cells is unknown at present. In this study, we demonstrated that the transcription of human nocturnin gene displayed circadian oscillations in Huh7 cells (a human hepatoma cell line) and was regulated by CLOCK/BMAL1 heterodimer via the E-box of nocturnin promoter. In addition, E-box2 is more efficient than E-box1 in the regulation of CLOCK/BMAL1 on nocturnin transcription in vitro.
Li
Ran
R
Department of Physiology, School of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, 100005, China.
Yue
Jiping
J
Zhang
Yu
Y
Zhou
Lan
L
Hao
Wei
W
Yuan
Jiangang
J
Qiang
Boqin
B
Ding
Jian M
JM
Peng
Xiaozhong
X
Cao
Ji-Min
JM
D056930:ARNTL Transcription Factors; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D056926:CLOCK Proteins; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D002940:Circadian Rhythm; D024721:E-Box Elements / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D008156:Luciferases; D009687:Nuclear Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C538960:BMAL1 protein, human; C102804:nocturnin; C538943:CLOCK protein, human