Cloning and characterization of the 5'-flanking region of the human transcription factor Sp1.

Nicolas M, Noe V, Jensen KB, Ciudad CJ.

J. Biol. Chem. Vol 276, 22126-22132 (2001)

Departamento de Bioqumica & Biol. Mol., University of Barcelona, Barcelona E-08028.

The 5'-flanking region of the human Sp1 gene was cloned and characterized. Sequence analysis of this regionshowed the absence of both

CAAT and TATA boxes and an initiator element. The proximal promoter of the Sp1

gene is a GC-rich region that contains multiple GC-boxes and Ap2 binding sites. The major transcription start site

is located 63 bp upstream of the translation start site. Transfection experiments demonstrate that all the elements

necessary to achieve significant basal transcription activity are located between positions -443 and -20 relative to the

translational start. Sp1 and Sp3 proteins bind to the downstream GC box located in the proximal promoter of Sp1.

We also demonstrate that Sp1 activates Sp1 transcription activity, thus the Sp1 gene is autoregulated.