KSHV ORF59 and PAN RNA Recruit Histone Demethylases to the Viral Chromatin during Lytic Reactivation.

Kayla Hiura,Subhash C Verma,Brian Prince,Roxanne Strahan,Timsy Uppal,Cyprian C Rossetto

doi:10.3390/v12040420

Abstract

Kaposi’s sarcoma-associated herpesvirus (KSHV) causes multiple malignancies in immunocompromised individuals. KSHV primarily establishes a lifelong latency in infected humans during which only a subset of viral genes is expressed while most of the viral genome remains transcriptionally silent with condensed chromatin. However, during the lytic phase, the viral genome undergoes dramatic changes in chromatin landscape leading to a transcriptionally active state with the expression of most of the viral genes and production of progeny virions. Multiple cellular and viral factors influence the epigenetic gene regulation and transitioning of virus from latency to the lytic state. We have earlier shown that KSHV ORF59, viral processivity factor, binds to a protein arginine methyl transferase 5 (PRMT5) to alter the histone arginine methylation during reactivation. Additionally, ORF59 has been shown to interact with most abundantly expressed KSHV long noncoding polyadenylated nuclear RNA (PAN RNA), which associates with the viral epigenome during reactivation. Interestingly, PAN RNA interacts with UTX and JMJD3, cellular H3K27me3 demethylases, and removes the repressive marks on the chromatin. In this study, we report that the recruitment of histone demethylases to the viral chromatin is facilitated by the expression of ORF59 protein and PAN RNA. Using biochemical and localization assays including co-immunoprecipitation and immunofluorescence, we demonstate ORF59 localizes with UTX and JMJD3. Our results confirm that PAN RNA enhances the interaction of ORF59 with the chromatin modifying enzymes UTX and JMJD3.

Highlights

Kaposi’s sarcoma-associated herpesvirus (KSHV), an oncogenic human γ-herpesvirus, is the cause of Kaposi’s Sarcoma [1,2,3], primary effusion lymphoma [4], KSHV inflammatory cytokine syndrome [5], and some forms of multicentric Castleman’s disease [6,7]
Previous studies have demonstrated that UTX and JMJD3 interact with polyadenylated nuclear RNA (PAN RNA) [25], which has been shown to interact with ORF59 [27]
We investigated if PAN RNA expression enhances the the binding of KSHV lytic protein ORF59 with these H3K27me3-specific histone demethylases

Summary

Introduction

Kaposi’s sarcoma-associated herpesvirus (KSHV), an oncogenic human γ-herpesvirus, is the cause of Kaposi’s Sarcoma [1,2,3], primary effusion lymphoma [4], KSHV inflammatory cytokine syndrome [5], and some forms of multicentric Castleman’s disease [6,7]. Most the viral genes (~90) are expressed in a synchronized manner, with the expression of immediate early (IE), early (E), and late (L) genes, leading to the amplification of viral DNA followed by packaging and release of virion particles [6,16]. This entire process starts with a change in the epigenetic architecture of viral promoters through the involvement of multiple viral and cellular proteins [6,10,17,18]

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Conclusion