Viral nucleoprotein (NP)

Viral nucleoprotein refers broadly to a family of essential structural and RNA-binding proteins found in numerous RNA and DNA viruses; it is best studied in negative-strand RNA viruses such as influenza, Ebola, and rabies. The nucleoprotein (NP) binds the viral genome, protecting it from nucleases and forming the core of the ribonucleoprotein (RNP) complex together with the viral RNA-dependent RNA polymerase. NP is central to replication and transcription, facilitating nuclear import of viral genomes (in the case of influenza) and organization of higher-order viral structures for packaging. Although the primary amino acid sequence and oligomerization state of NP can vary greatly between virus families, its role in genome encapsidation and support of viral gene expression is universal[1][3][4][6][11][12]. The high conservation and essentiality of NP make it both a diagnostic marker and an attractive—though challenging—therapeutic target. Some antivirals and diagnostics exploit NP structure and function for virus detection and inhibition.

Other names

NucleoproteinNPViral NPN protein (for some viruses)Nucleocapsid protein (for some viruses, though this is often a separate, but related term)

Inhibition of RNA binding/packaging (e.g., small molecules disrupting NP-RNA interaction); Inhibition of oligomerization and RNP assembly; Inhibition of nuclear import/export signals (influenza); Interference with nucleoprotein essential for viral replication/transcription