Regulation of the pluripotency marker Rex-1 by Nanog and Sox2.
Rex-1 (Zfp-42) is a known marker for undifferentiated embryonic stem cells and teratocarcinoma cells. However, the mechanism by which Rex-1 is regulated in pluripotent cells remains unresolved. Here we report that Nanog, an Nk-2 homeodomain protein known for its role in maintaining stem cell pluripotency, is a transcription activator for the Rex-1 promoter. Knockdown of Nanog in embryonic stem cells resulted in a reduction of Rex-1 expression, whereas forced expression of Nanog in P19 stimulated Rex-1 expression. Employing a Rex-1 reporter, we demonstrate that Nanog transactivates Rex-1 directly. Serial deletion studies mapped the Nanog-responsive element between -187 and -286 of the Rex-1 promoter. Although Oct-3/4 and Sox2 can both transactivate Rex-1 promoter, only Sox2 cooperates with Nanog in up-regulating Rex-1. Furthermore, we demonstrate that the C terminus of Nanog is responsible for transactivating the Rex-1 promoter, a function that can be substituted for by a viral transactivator Vp16 efficiently in NIH3T3 cells but less so in P19 cells. Taking these findings together, we conclude that Rex-1 is a direct target of Nanog, which is augmented by Sox2 and Oct-3/4.
Shi
Wenjing
W
Institute of Pharmacology, Department of Biological Sciences & Biotechnology, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institutes of Biomedicine, School of Medicine, Tsinghua University, Beijing 100084, China.
Wang
Hui
H
Pan
Guangjin
G
Geng
Yijie
Y
Guo
Yunqian
Y
Pei
Duanqing
D
D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D018398:Homeodomain Proteins / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D051379:Mice; D041681:NIH 3T3 Cells; D000071317:Nanog Homeobox Protein; D039904:Pluripotent Stem Cells / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D020218:Response Elements; D055748:SOXB1 Transcription Factors; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
D015415:Biomarkers; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D051741:Kruppel-Like Transcription Factors; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; C513672:Zfp42 protein, mouse; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; C507976:ZFP42 protein, human