Herpesvirus-mediated mRNA destruction

herpes virus

Our lab’s interests lie in dissecting how viruses interface with the pathways that govern messenger RNA turnover.  The ability to regulate RNA stability has the potential to impact gene expression on a global scale, but is also critical for fine-tuning cellular responses to specific stimuli as well as eliminating flawed and potentially deleterious transcripts.  We seek to pinpoint viral targets within these pathways so as to better understand mechanisms by which viruses regulate their own messages and/or eliminate potentially competitive or antiviral cellular transcripts.  We anticipate that these studies will also enhance our understanding of how such important pathways are normally regulated in human cells.

Our models are γ-herpesviruses such as Kaposi’s sarcoma-associated herpesvirus (KSHV), as these agents promote global cellular mRNA destruction during their lytic replication cycle.  A critical viral effector of this phenotype is called SOX (encoded by ORF37 in KSHV and MHV68).  We hypothesize that SOX deregulates one or more cellular RNA degradation pathways to achieve host shutoff.
 

How do viral & some cellular transcripts selectively evade turnover?

KSHV mRNAs look essentially like cellular transcripts; many are spliced, and they are transcribed and processed using cellular machinery. How does host shutoff affect the stability of these viral mRNAs, and what implications does this have for viral fitness?

What cellular pathways and proteins are required to promote global cellular mRNA destruction by γ-herpesviruses?

We are conducting genome-wide screening experiments to identify the composite of cellular factors either directly targeted by the KSHV host shutoff factor SOX (and its homologs) or involved as downstream effectors of mRNA destruction in SOX-expressing cells. We are also interested in determining whether the regulation of key mRNA turnover enzymes and pathways is altered during viral infection, and whether these pathways are required for viral replication. Finally, we are exploring how SOX-induced alterations in RNA processing influence RNA stability, localization, and gene expression in cells.