E4F1

The zinc finger protein encoded by this gene is one of several cellular transcription factors whose DNA-binding activities are regulated through the action of adenovirus E1A. A 50-kDa amino-terminal product is generated from the full-length protein through proteolytic cleavage. The protein is differentially regulated by E1A-induced phosphorylation. The full-length gene product represses transcription from the E4 promoter in the absence of E1A, while the 50-kDa form acts as a transcriptional activator in its presence.^[7]

E4F1 has been shown to interact with:

• P16,^[8]
• P53,^[8][9] and
• RB1^[10]