The E2F family of transcription factors plays a crucial role in the control of cell cycle [, ]and action of tumour suppressor proteins. This family consists of eight members and is divided into activators (E2F1-3) and repressors (E2F4-8) depending on cellular context, target gene and cofactors []. The E2F proteins contain several evolutionarily conserved domains found in most members of the family. These domains include a DNA-binding domain, a dimerisation domain which determines interaction with the differentiation regulated transcription factor proteins (DP), a transactivation domain enriched in acidic amino acids, and a tumour suppressor protein association domain which is embedded within the transactivation domain []. Classical E2Fs (E2F1-6) contain one DNA-binding domain which form heterodimers with DP proteins; atypical family members, E2F7 and E2F8, possess two DNA-binding domains, form homodimers or heterodimers, thus regulating transcription in a DP-independent manner [].
