REGULATION OF TRANSCRIPTION BY E2F1 DP1

The E2F1 transcription factor, in co-operation with DP1, controls the expression of several S-phase specific genes. This activity is most li kely responsible for the oncogenic and S-phase inducing properties of E2F1, suggesting that this transcription factor plays a key role in re gulating the cell cycle. The transcriptional activation functions of E 2F1 are resident in a small C-terminal domain which can independently activate transcription. Here we review the protein-protein interaction s which impinge upon and regulate this activation domain and put forwa rd some models on their mechanism of action.