SOX17 directly activates Zfp202 transcription during in vitro endoderm differentiation.
SOX17 is a SRY-related high-mobility group (HMG) box transcription factor that is necessary for endoderm formation in multiple species. Despite its essential function during endoderm formation and differentiation, few direct targets of SOX17 are known. To identify targets of SOX17, we isolated SOX17 binding sites with a chromatin immunoprecipitation (ChIP)-cloning screen. SOX17-ChIP identified zinc finger protein 202 (Zfp202) as a direct target of SOX17 during endoderm differentiation of F9 embryonal carcinoma cells. A sequence in the first intron of Zfp202 activated transcription in differentiated F9 cells, and overexpression of Sox17 increased the transcriptional activity of this sequence. SOX17 binds to a site within this sequence in electrophoretic mobility shift assays, and mutation of this site decreases the transcriptional activation. Zfp202 is induced concomitantly with Sox17 during endoderm differentiation of F9 cells. We also show that ZFP202 represses Hnf4a, which has been reported for the human ortholog ZNF202. Identifying targets of SOX17 will help to elucidate the molecular basis of endoderm differentiation and may provide a better understanding of the role of endoderm in patterning the other germ layers.
Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA. espatterson@wustl.edu
Ethan S
ES
Patterson
Russell C
RC
Addis
Michael J
MJ
Shamblott
John D
JD
Gearhart
D000818:Animals; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D002999:Clone Cells; D003001:Cloning, Molecular; D024202:Electrophoretic Mobility Shift Assay; D047108:Embryonic Development / Q000235:genetics; D004707:Endoderm / Q000166:cytology*; D018507:Gene Expression Regulation, Developmental; D051557:Hepatocyte Nuclear Factor 4 / Q000235:genetics; D006801:Humans; D051379:Mice; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D055760:SOXF Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D051557:Hepatocyte Nuclear Factor 4; C496593:Hnf4a protein, mouse; D012097:Repressor Proteins; C109188:SOX17 protein, human; D055760:SOXF Transcription Factors; C115745:ZNF202 protein, human