Adenovirus early region 1 protein (E1)

Adenovirus early region 1 (E1) protein refers to a group of essential viral proteins, primarily E1A and E1B, that orchestrate the early stages of the adenoviral life cycle (UniProt P03255, P03247). E1A acts as a master transcriptional regulator and oncoprotein that forces quiescent host cells into the S-phase of the cell cycle by sequestering the retinoblastoma (pRb) protein, thereby facilitating viral DNA replication (Wikipedia). E1B proteins, specifically E1B-19K and E1B-55K, complement this by inhibiting E1A-induced apoptosis and blocking host antiviral defenses such as p53 and interferon signaling (NIH). In therapeutic contexts, the E1 region is a critical target for genetic engineering; its deletion is the standard method for creating replication-deficient vectors for gene therapy and vaccines, such as those used for COVID-19 (PNAS). Furthermore, selective modifications of E1 are employed to develop oncolytic viruses like ONYX-015, which preferentially replicate in p53-deficient cancer cells (NIH). While no drugs specifically targeting E1 are currently FDA-approved, research has identified Hsp90 inhibitors like 17-AAG (Tanespimycin) as potential antivirals that reduce E1A protein stability and viral titers (MDPI).

Other names

Early region 1 proteinE1A proteinE1B proteinAdenovirus early region 1A proteinAdenovirus early region 1B proteinE1A 289RE1A 243RE1B-55KE1B-19KEarly E1A proteinEarly E1B protein

Inhibition of viral replication through the disruption of E1A protein stability via Hsp90 inhibition, or the genetic deletion of E1 sequences to create replication-deficient or tumor-selective viral agents.