RNase L-mediated RNA decay alters 3' end formation and splicing of host mRNAs
The antiviral endoribonuclease, RNase L, is a vital component of the mammalian innate immune response that destroys host and viral RNA to reduce viral gene expression. Herein, we show that a consequence of RNase L-mediated decay of cytoplasmic host RNAs is the widespread re-localization of RNA-binding proteins (RBPs) from the cytoplasm to the nucleus, due to the presence of nuclear RNA. Concurrently, we observe global alterations to host RNA processing in the nucleus, including alterations of splicing and 3 end formation, with the latter leading to downstream of gene (DoG) transcripts. While affecting many host mRNAs, these alterations are pronounced in mRNAs encoding type I and type III interferons and coincide with the retention of their mRNAs in the nucleus. Similar RNA processing defects also occur during infection with either dengue virus or SARS-CoV-2 when RNase L is activated. These findings reveal that the distribution of RBPs between the nucleus and cytosol is fundamentally dictated by the availability of RNA in each compartment and thus viral infections that trigger cytoplasmic RNA degradation alter RNA processing due to the nuclear influx of RNA binding proteins.