RT Journal Article
SR Electronic
T1 An evolutionarily conserved strategy for ribosome binding and inhibition by β-coronavirus non-structural protein 1
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2023.06.07.544141
DO 10.1101/2023.06.07.544141
A1 Stephanie F. Maurina
A1 John P. O’Sullivan
A1 Geetika Sharma
A1 Daniel C. Pineda Rodriguez
A1 Andrea MacFadden
A1 Francesca Cendali
A1 Morkos A. Henen
A1 Jeffrey S. Kieft
A1 Anum Glasgow
A1 Anna-Lena Steckelberg
YR 2023
UL http://biorxiv.org/content/early/2023/06/08/2023.06.07.544141.abstract
AB An important pathogenicity factor of SARS-CoV-2 and related coronaviruses is Nsp1, which suppresses host gene expression and stunts antiviral signaling. SARS-CoV-2 Nsp1 binds the ribosome to inhibit translation through mRNA displacement and induces degradation of host mRNAs through an unknown mechanism. Here we show that Nsp1-dependent host shutoff is conserved in diverse coronaviruses, but only Nsp1 from β-CoV inhibits translation through ribosome binding. The C-terminal domain of all β-CoV Nsp1s confers high-affinity ribosome-binding despite low sequence conservation. Modeling of interactions of four Nsp1s to the ribosome identified few absolutely conserved amino acids that, together with an overall conservation in surface charge, form the β-CoV Nsp1 ribosome-binding domain. Contrary to previous models, the Nsp1 ribosome-binding domain is an inefficient translation inhibitor. Instead, the Nsp1-CTD likely functions by recruiting Nsp1’s N-terminal “effector” domain. Finally, we show that a viral cis-acting RNA element has co-evolved to fine-tune SARS-CoV-2 Nsp1 function, but does not provide similar protection against Nsp1 from related viruses. Together, our work provides new insight into the diversity and conservation of ribosome-dependent host-shutoff functions of Nsp1, knowledge that could aide future efforts in pharmacological targeting of Nsp1 from SARS-CoV-2, but also related human-pathogenic β-coronaviruses. Our study also exemplifies how comparing highly divergent Nsp1 variants can help to dissect the different modalities of this multi-functional viral protein.Competing Interest StatementThe authors have declared no competing interest.