Nuclear translocation of spike mRNA and protein is a novel pathogenic feature of SARS-CoV-2.

One of the novel sequence insertions resides at the S1/S2 boundary of Spike (S) protein and constitutes a functional nuclear localization signal (NLS) motif "PRRARSV", which may supersede the importance of previously proposed polybasic furin cleavage site "RRAR". Indeed, S protein's NLS-driven nuclear translocation and its possible role in S mRNA's nuclear translocation reveal a novel pathogenic feature of SARS-CoV-2.