Recombinant Human herpesvirus 1 Virion host shutoff protein (UL41)

Minor structural protein that acts as an endoribonuclease during lytic infection. Degrades host mRNAs in the cytoplasm by cutting them at preferred sites, including some in regions of translation initiation. Together with inhibition of host splicing by ICP27, contributes to an overall decrease in host protein synthesis. Also, after the onset of viral transcription, accelerates the turnover of viral mRNA, thereby facilitating the sequential expression of different classes of viral genes. Binds translation initiation factors eIF4H, eIF4AI, and eIF4AII, thereby may interact directly with the translation initiation complex and thus digest specifically mRNAs. Also impedes antigen presentation by major histocompatibility complex class I and class II molecules, inhibits secretion of cytokines that would otherwise recruit lymphocytes and neutrophils cells to the site of infection and blocks the activation of dendritic cells. Plays a role in the inhibition of interferon-beta activation by the cGAS/STING pathway. Mechanistically, downregulates the expression of host cGAS/MB21D1. Decreases also the accumulation of other interferon-induced mRNAs such as host IFIT3 or CH25H to subvert their antiviral activity.