Human cytomegalovirus immediate-early protein 2 (IE2)

Human cytomegalovirus immediate-early protein 2 (IE2) is a multifunctional viral transcription factor encoded by the UL122 locus of the HCMV genome. It is expressed early after infection as three major isoforms (p86, p60, p40). IE2 directly binds viral DNA, activates and represses viral gene transcription—including autoregulation of the immediate-early promoter—and is essential for progression of the viral lytic cycle. IE2 orchestrates the formation of viral replication compartments in the host cell nucleus and interacts dynamically with host transcription factors (TBP, TFIIB, and chromatin modifiers). Beyond its viral regulatory activities, IE2 modulates host cell signaling, promotes G1/S cell cycle transition, and arrests S phase progression, preventing host DNA replication while favoring viral replication. IE2 also antagonizes host immune signaling by downregulating interferon-β and inflammatory chemokine responses. These diverse regulatory actions make IE2 a key determinant of HCMV infection, pathogenesis, and persistence.

Other names

Immediate-early protein 2 (IE2)UL122 (HCMV genome locus)86 kDa immediate-early protein 2 (isoform p86)60 kDa immediate-early protein 2 (isoform p60)40 kDa immediate-early protein 2 (isoform p40)

Not directly applicable; hypothetical or experimental drugs would act by: - Inhibiting IE2-DNA binding - Blocking IE2-mediated transcriptional regulation - Interfering with protein-protein interactions between IE2 and host or viral factors