Characterization of putative cis-regulatory elements that control the transcriptional activity of the human Oct4 promoter.
Octamer-binding transcription factor-4 (Oct4), a member of the POU domain transcription factors, is crucial for both early embryonic development and the maintenance of stem cell pluripotency. The human Oct4 (hOct4) 5' upstream sequence contains four conserved regions (CR1, 2, 3, 4) that are homologous in the murine. In this study, we constructed a series of deletion mutants of the hOct4 5' upstream region and identified cis-regulatory elements that may be important determinants for the transcriptional activity of the hOct4 promoter. Our studies showed that CR2, 3, and 4 each acted as positive cis-regulatory elements in hOct4 promoter activity. We also newly identified a putative negative cis-acting element located between CR1 and CR2. In addition, the sequence -380/-1 at CR1 that contains a GC box was sufficient to provide the minimal promoter activity. Site-directed mutagenesis and electrophoretic mobility shift assays revealed the GC box located in the -380/-1 region may play a critical role in controlling the transcriptional activity of hOct4 by the direct binding of Sp1 or Sp3 transcription factors to the GC box. An overexpression study showed that Sp1 and Sp3 positively and negatively regulate hOct4 promoter activity. Thus, the hOct4 promoter upstream region contains multiple regulatory elements, one of which, the GC box, may be an important cis-regulatory element that regulates the transcription of the hOct4 promoter by the binding of Sp family transcription factors.
Yang
Heung-Mo
HM
Cell and Gene Therapy Research Institute, Graduate School of Life Science and Biotechnology, Pochon CHA University, 606-13, Seoul, South Korea.
Do
Hyun-Jin
HJ
Oh
Jong-Hyun
JH
Kim
Jin-Hoi
JH
Choi
Sang-Yun
SY
Cha
Kwang-Yul
KY
Chung
Hyung-Min
HM
Kim
Jae-Hwan
JH
D001483:Base Sequence; D045744:Cell Line, Tumor; D020862:GC Rich Sequence / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D017930:Genes, Reporter; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D016415:Sequence Alignment; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051705:Sp3 Transcription Factor / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*; D014162:Transfection
D009687:Nuclear Proteins; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D016329:Sp1 Transcription Factor; D051705:Sp3 Transcription Factor