Adenoviral Early Region 1A protein (E1A)

Adenoviral Early Region 1A (E1A) is a multifunctional phosphoprotein and the first viral gene product synthesized following adenovirus infection. It serves as a master regulator of the viral life cycle by hijacking host cell machinery to initiate viral DNA replication and transcription (Berk, 2005, FEBS Letters). E1A primarily functions by binding to key cellular tumor suppressors, most notably the Retinoblastoma (Rb) protein and the p300/CBP transcriptional co-activators, thereby forcing the cell into the S-phase of the cell cycle (Whyte et al., 1988, Nature). In oncology, E1A is utilized in gene therapy and oncolytic viruses due to its ability to induce apoptosis and repress the expression of certain oncogenes like HER2/neu (Frisch & Mymryk, 2002, Nature Reviews Cancer). Therapeutic strategies often involve modifying the E1A gene to ensure selective replication in tumor cells or using it as a sensitizing agent for chemotherapy and radiotherapy. Despite its potential, challenges include the high immunogenicity of the adenoviral delivery vectors and the risk of systemic toxicity (UniProt, P03255).

Other names

Early region 1A proteinAd5 E1AAdenovirus E1AE1A oncoproteinTranscription regulator E1A

Induction of host cell S-phase entry via Retinoblastoma (Rb) protein inactivation and modulation of p300/CBP-mediated transcription to promote viral replication or therapeutic apoptosis.