The N protein of PEDV
The N protein of PEDV, consisting of 441 amino acids, is the only
phosphorylated
nucleocapsid
protein among the known structural proteins of coronaviruses. Previous
investigation on the cellular distribution of the N protein indicated
that it is mainly located in the cytoplasm, with some N proteins in the
nucleus of PEDV infected Vero cells (Shi D et al., 2014). The
multifunctional property of the N protein manifests in several aspects:
1) it is bound by viral RNA to provide a structural basis for the helix
nucleocapsid, while the resultant product is recognized by M protein
through the interaction between the N protein and C-terminal domain of
the M protein (aa237-252), and then packaged into virus particles to
form the core of coronavirus (Shi D et al., 2017); 2) as an alkaline
phosphoprotein, the N protein is also associated with virus replication
and transcription (YW, S, H, J, & DX, 2006); 3) its participation in
the biological processes related to PEDV survival has been affirmed (Shi
D et al., 2017; K. N et al., 2019); 4) its localization in the nucleus
may be associated with the regulation of host cell cycle and the
promotion of PEDV replication process (X et al., 2013). For instance,
the interaction of it with Nucleophosmin 1 (NPM1) protects NPM1 from
proteolysis, thereby improving cell survival rate and affecting the
replication process of PEDV (Shi D et al., 2017).