Immediate-early protein ICP27 (ICP27) (ICP27)

Immediate-early protein ICP27 (ICP27) is an essential regulatory protein encoded by the UL54 gene of Herpes Simplex Virus (HSV) [1]. As a multifunctional protein, it plays a central role in the viral life cycle by coordinating the transition from immediate-early to early and late gene expression [2]. ICP27 primarily functions by inhibiting host cell pre-mRNA splicing and facilitating the nuclear export of viral mRNAs, which are typically intronless, through interactions with the host export receptor TAP/NXF1 [3, 4]. It also interacts with the C-terminal domain of RNA polymerase II to influence viral transcription and has been shown to modulate the host immune response by interfering with Type I interferon signaling [5]. Because ICP27 is essential for viral replication and highly conserved across the Alphaherpesvirinae subfamily, it represents a promising therapeutic target for the development of next-generation antivirals [6]. Current drug discovery efforts focus on small molecules that can disrupt its protein-protein or protein-RNA interactions, offering a potential strategy to overcome resistance to traditional nucleoside analogs like acyclovir [7]. These inhibitors aim to block the viral replication cycle at an earlier stage than current therapies, potentially reducing viral shedding and latency reactivation [8].

Other names

Infected cell protein 27UL54Regulatory protein ICP27IE63 homologImmediate-early protein 63

Inhibition of viral mRNA nuclear export and disruption of the transition to late viral gene expression.