RT Journal Article SR Electronic T1 Potential coupling between SARS-CoV-2 replicative fitness and interactions of its nucleoprotein with human 14-3-3 proteins JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.12.23.474009 DO 10.1101/2021.12.23.474009 A1 Tugaeva, Kristina V. A1 Sysoev, Andrey A. A1 Smith, Jake L. R. A1 Cooley, Richard B. A1 Antson, Alfred A. A1 Sluchanko, Nikolai N. YR 2021 UL http://biorxiv.org/content/early/2021/12/25/2021.12.23.474009.abstract AB The SARS-CoV-2 nucleocapsid protein (N) is responsible for the viral genome packaging and virion assembly. Being highly abundant in the host cell, N interacts with numerous human proteins and undergoes multisite phosphorylation in vivo. When phosphorylated within its Ser/Arg-rich region, a tract highly prone to mutations as exemplified in the Omicron and Delta variants, N recruits human 14-3-3 proteins, potentially hijacking their functions. Here, we show that in addition to phosphorylated Ser197, an alternative, less conserved phosphosite at Thr205, absent in SARS-CoV N, binds 14-3-3 with micromolar affinity and is in fact the preferred binding site. Fluorescence anisotropy reveals a distinctive pT205/pS197 binding selectivity towards the seven human 14-3-3 isoforms. While explaining the structural basis for the discovered selectivity towards SARS-CoV-2 N phosphopeptides, our crystal structures enable prediction of N interactions with 14-3-3, suggesting a link between the strength of this interaction and replicative fitness of emerging coronavirus variants.Competing Interest StatementThe authors have declared no competing interest.