Isolation, characterization, and differential expression of the murine Sox-2 promoter

So?: proteins are expressed at many stages of development and in numerous t issues. The transcription factor Sox-2 is first expressed throughout the in ner cell mass and subsequently becomes localized to the primitive ectoderm, developing central nervous system, and the lens. Sox-2 is also highly expr essed in F9 embryonal carcinoma cells, but becomes undetectable following d ifferentiation of these cells. In this study, we have isolated, sequenced, and performed the first characterization of the Sox-2 promoter of any speci es. Approximately 2 kb of the Sox-2 5'-flanking region has been sequenced a nd the primary transcription start site mapped by primer extension analysis . Additionally, two positive regulatory regions within the promoter region have been identified. We also show that expression of Sox-2 promoter/report er gene constructs is reduced in differentiated EC cells as compared to the ir undifferentiated counterparts. Furthermore, we have identified a consens us inverted CCAAT box motif present in the Sox-2 promoter. Mutagenesis of t his site significantly reduces the expression of Sox-2 promoter/reporter co nstructs. We also demonstrate that this CCAAT box motif can bind the trimer ic transcription factor NF-Y. (C) 2000 Published by Elsevier Science B.V. A ll rights reserved.