The influenza virus nucleoprotein: a multifunctional RNA-binding protein pivotal to virus replication

TLDR

Negative‑sense RNA viruses encode a nucleoprotein that encapsidates the genome for transcription, replication, and packaging, and interacts with diverse viral and host proteins. The review demonstrates that influenza NP is more than a structural RNA‑binding protein; it also acts as a key adapter between virus and host cell processes. The review examines evidence for NP’s multiple activities and their roles in transcription, replication, and intracellular trafficking of the viral genome.

Abstract

All viruses with negative-sense RNA genomes encode a single-strand RNA-binding nucleoprotein (NP). The primary function of NP is to encapsidate the virus genome for the purposes of RNA transcription, replication and packaging. The purpose of this review is to illustrate using the influenza virus NP as a well-studied example that the molecule is much more than a structural RNA-binding protein, but also functions as a key adapter molecule between virus and host cell processes. It does so through the ability to interact with a wide variety of viral and cellular macromolecules, including RNA, itself, two subunits of the viral RNA-dependent RNA polymerase and the viral matrix protein. NP also interacts with cellular polypeptides, including actin, components of the nuclear import and export apparatus and a nuclear RNA helicase. The evidence for the existence of each of these activities and their possible roles in transcription, replication and intracellular trafficking of the virus genome is considered.