E2F1 binds to E2F binding sites in the promoter of the POLA1 gene, stimulating POLA1 transcription. POLA1 encodes the catalytic subunit p180 of the DNA polymerase alpha (DeGregori et al. 1995, Giangrande et al. 2004). Activation of POLA1 by E2F1 has also been demonstrated in Drosophila (Ohtani and Nevins 1994).