RNA degradation broadly controls viral transcript abundance

What is it about?

Many viruses restrict host gene expression during infection, presumably to provide a competitive expression advantage to viral transcripts. Not surprisingly, viruses that induce this ‘host shutoff’ phenotype therefore generally possess mechanisms to selectively spare viral genes. Gammaherpesviruses promote host shutoff by inducing widespread mRNA degradation. Here, we reveal that during infection with MHV68, the majority of viral transcripts of all classes are regulated by RNA degradation.

Featured Image

Why is it important?

In the absence of degradation-induced control of viral mRNA abundance, viral protein levels increase, thereby affecting the composition of progeny viral particles and the outcome of subsequent rounds of infection. This is the first example of a eukaryotic virus whose host shutoff mechanism similarly tempers viral gene expression, and highlights the degree to which gammaherpesviral gene expression must be fine tuned to ensure replicative success.