Sp1 and CTF/NF-1 transcription factors are involved in the basal expression of the Hmgi-c proximal promoter.
HMGI-C is a nuclear architectural factor which is expressed during embryogenesis but not in adult tissues while it becomes re-expressed following neoplastic transformation. In this paper we identify the promoter region of the mouse Hmgi-c gene and by stepwise deletion of the 5' sequences we map the promoter activity of the most abundant transcript to a very short fragment containing a long polypyrimidine/polypurine (ppyr/ppur) tract. We demonstrate that this tract is a multiple binding site for the transcription factors Sp1 and Sp3 and that in Drosophila SL2 cells, Sp1 activates the Hmgi-c promoter. In addition, another transcription factor, CTF/NF-1, binds the proximal promoter immediately downstream of this region and its mutation decreases transcription in NIH-3T3 cells. This study identifies factors responsible for the basal activity of Hmgi-c gene and provides a foundation for further analysis of the mechanism of its regulation.
Rustighi
A
A
Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, Trieste, Italy.
Mantovani
F
F
Fusco
A
A
Giancotti
V
V
Manfioletti
G
G
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004330:Drosophila; D005786:Gene Expression Regulation; D025743:HMGA2 Protein; D006609:High Mobility Group Proteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D011401:Promoter Regions, Genetic; D016601:RNA-Binding Proteins / Q000378:metabolism*; D017384:Sequence Deletion; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000378:metabolism*; D018911:Trinucleotide Repeats
D022762:CCAAT-Enhancer-Binding Proteins; C077305:CTF-1 transcription factor; D017931:DNA Primers; D004268:DNA-Binding Proteins; D025743:HMGA2 Protein; D006609:High Mobility Group Proteins; D051839:NFI Transcription Factors; D016601:RNA-Binding Proteins; D016329:Sp1 Transcription Factor; C497122:Sp3 protein, mouse; D014157:Transcription Factors; D051705:Sp3 Transcription Factor; D004247:DNA