The N-terminal domain of Sp2 can rescue target gene expression.

<p>(A) The N-terminal domain of Sp2 has the capacity to activate transcription. The Gal4 DNA-binding domain (Gal4), and Gal4-Sp1NT and Gal4-Sp2NT fusions were transfected into HEK293 cells along with a 5xUAS-luciferase reporter construct. Fold activation by Gal4-Sp1NT and Gal4-Sp2NT is expressed relative to the Gal4 DNA-binding domain set to 1. (B, C) Relative expression of the <i>Nlk</i> (B), <i>Grb2</i> and <i>Oxr1</i> (C) genes in wt MEFs, <i>Sp2ko</i> MEFs and in <i>Sp2ko</i> MEFs re-expressing full-length Sp2 (Sp2FL) or the Sp2NT and Sp2ZF mutants. (C) Schematic representation of the exon-intron structures of the <i>Grb2</i> and <i>Oxr1</i> genes and the promoters bound by either Sp1/Sp3 or by Sp2. The primer pairs P1-P2 detect specifically transcripts derived from the Sp2-bound promoters. The primer pairs P3-P4 detect all transcripts. Transcript levels in wt MEFs determined by qPCR were set to 1. <i>Gapdh</i> mRNA levels were used for normalization. Data are presented as the average of three independent experiments +/-SD.</p>